KymcoForum.com
General => Technical | How To => Topic started by: 245luigi on October 03, 2013, 01:12:40 PM
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Hello all,
Warning, many questions ahead! Now that the riding season is calming down in my area (Baltimore, MD), I have decided to install a BBK on my Like 50 during the winter. I have done alot of research on the forum here as well as other places. Now im looking for some feedback on my shopping list as well as how the heck Im going to tune this thing once all the parts come in.
First off, current setup: 2012 Like 50, Stock Kiehin PB 16 with 86 MJ and 35 PJ, Tecnigas Next R Exhaust, Stock Airbox
For this upgrade I plan on getting:
Malossi Cylinder Kit
http://www.racingplanetusa.com/cylinder-malossi-sport-with-head-70cc-kymco-horizontal-p-228-1.html?cPath=2_26378_26380&sessID=fdb133b4fb42f31519cb44d0a0acc53e (http://www.racingplanetusa.com/cylinder-malossi-sport-with-head-70cc-kymco-horizontal-p-228-1.html?cPath=2_26378_26380&sessID=fdb133b4fb42f31519cb44d0a0acc53e)
Malossi Carb Kit (Come with 19mm Dell'Orto PHBG)
http://www.racingplanetusa.com/carburetor-malossi-phbg-kymco-sf10-p-314-1.html?cPath=2_26378_26380&sessID=fdb133b4fb42f31519cb44d0a0acc53e (http://www.racingplanetusa.com/carburetor-malossi-phbg-kymco-sf10-p-314-1.html?cPath=2_26378_26380&sessID=fdb133b4fb42f31519cb44d0a0acc53e)
20mm Intake manifold
http://www.racingplanetusa.com/intake-manifold-20mm-racing-kymco-p-250-1.html?cPath=2_26378_26380&sessID=fdb133b4fb42f31519cb44d0a0acc53e (http://www.racingplanetusa.com/intake-manifold-20mm-racing-kymco-p-250-1.html?cPath=2_26378_26380&sessID=fdb133b4fb42f31519cb44d0a0acc53e)
20mm Intake/Carb Spacer
http://www.racingplanetusa.com/spacer-20mm-intake-manifold-insulator-spacer-20mm-with-oring-p-2284-1.html?sessID=fdb133b4fb42f31519cb44d0a0acc53e (http://www.racingplanetusa.com/spacer-20mm-intake-manifold-insulator-spacer-20mm-with-oring-p-2284-1.html?sessID=fdb133b4fb42f31519cb44d0a0acc53e)
I also would like to go to Open Airbox during this conversion but I have no idea what kind of connection there would be between the Dell'Orto and the Open Air Filter. I dont know the size, as I havent been able to find any specs on the opening. Any input?
Now to jetting. I have no idea what jets the Dell'Orto comes with installed. I also dont even know where to begin with jetting trials. Im looking for some input as to a range of jets to pickup. I do know this, on the stock PB 16, with open airbox, I was using a 105 - 108 MJ, getting good chops and 38 PJ for a nice idle. Moral of the story here is I have never started from 0 with a carb. I've just had the experience of having a tuned carb and changing jets when I've messed with the airflow some how (exhaust duh!). Also how does one do plug chops during break in? I know WOT is bad but how else am I supposed to dial in my main jet?
Sorry for the stream of consciousness here but any and all input is extremely appreciated!
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I also would like to make sure the squish band is at the right spacing but Im having trouble finding which gaskets to use. I dont know if the stock kymco gaskets would fit or if I have to change over to Malossi ones. Also I havent found a resource for gaskets that I know would fit the 70cc kit and have options for different thicknesses.
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Actually I believe the cylinder head has an o ring type gasket so forget the squish band question
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What is the purpose of the tuning? Is it it get more power, increase max speed or everything at once? Personally I would do one upgrade at the time and not everything at once. That way you have more control on what is happening. A 70cc will run just fine on your stock carb as long as you re-jet it and move the needle. My advice is to install the bigger cylinder first, run it in and then consider the bigger carb. The mallossi is a cast iron cylinder so it will need to be broken in for some time before you can start to fine tune. As to the main jet size I won't recommend a specific size as I have worked on different scooters than yours and results may wary. Sound and feel are also good indicators on jetting. A few years since my last two stroke, but when I was at my game I only needed plug-chops as a confirmation and tuned by sound and feel exclusively. There are several guides on the net, so I won't reiterate it here. Either way I would jet on the rich side until your cylinder is properly broken in (and that can take a while) Do you have a unrestricted CDI? No point in huge air supply if the rpms are hard capped.
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Haarek is right.. a step at a time so you can really feel the difference of each upgrade and know what to do next...
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The purpose I'm tuning is because I have fun messing with my scooter! I'm looking to increase max speed. I find it thrilling trying to squeeze every last drop out of this thing. I absolutely agree with the 1 step at a time idea; always works whether its diagnosing issues, CVT tuning, or jetting after playing with your exhaust or airbox.
Haarek I wish I could tune by sound/feel. Thats very interesting.
I will install each part starting with cylinder and stock carb (I have MJ 78 - 120 and PJ 35 - 40). The reason I included the carb in my list is because all of the shops selling the cylinder kit + Like50 owners in the KF archive have said you need 17.5mm at least when going to 70cc. My guess is ill have to richen the stock carb settings when I put on the 70cc cylinder. When I first bolt on a brand new carb how do I figure my starting point with jets? Just ballpark and go?
I dont know if I have an unrestricted CDI. I probably do. Thing is its really hard to find Like50 info out there; this forum has definitely been my best source. I still have yet to find a Like owner, here or some other forum that has messed with the stock CDI. When I did so open airbox jetting trials on the stock cylinder and tecnigas exhaust I was able to get ~5mph more out of my stock setup.
Thanks for the feedback
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Here are some tips on how to tune by "feel". I copied it a few years ago from a site I don't remember the name of. Credit goes to "that" site ;D
The following advice is targeted at Keihin carbs, but the principles are the same for every carburettor. Notice the tuning is done without plug-chops until the very end :)
Rich Jetting Symptoms and Solutions
- Motor won't idle well and idle set screw won't work effectively. Try leaning out the air screw by turning it counter clockwise a quarter turn at a time. If the air screw has no effect, install a leaner pilot jet and return the air screw to 1 turn out. Proper air screw settings are usually between 1 and 2 1/2 turns out. The correct pilot for your bike is one that allows instant off-idle throttle response, and allows the air screw to be effective between 1 and 2.5 turns out. If the problem still exists, check and clean the choke circuit and carb vent lines.
- Motor stumbles off idle to 1/2 throttle, then cleans up. If everything in part A above is correct, check the needle. Stock position is usually in the middle, but check your owner's manual to be sure. To lean out the needle, you need to raise the clip. If the needle is dropped all the way lean and problem still exists, try a leaner needle.
- Motor will run through the mid range then becomes gurgley (technical term) at full throttle and power is sluggish. This is a text book example of a rich main jet. This problem often occurs when an air filter becomes clogged and gets worse as the motor heats up. Choose a main jet with a smaller number and lean out the air fuel mixture one step at a time. If the problem still persists even though it's improved a little, reinstall your original main jet and lean out the needle one position. Now fine tune the main jet with plug checks.
Lean Jetting Symptoms and Solutions
- Motor hesitates off idle with a "Boooooooooowang" sound. This is a lean symptom and often occurs when a motor is cold. Try turning the air-fuel screw clockwise a quarter turn richer and check throttle response again until motor revs without hesitation. If the motor "hangs up" or doesn't come right back down to idle, install a richer pilot, and reset air screw.
- Motor knock knock knocks at idle when hot. Try solution A. If problem persists, perform a "leakdown pressure test" to check for ignition crank seal leakage.
- Motor revs clean and crisp but runs really hot and lacks power. This symptom indicates a lean main jet and/or needle. Use a richer main jet and/or needle setting. This is the most common misconception about two stroke jetting: When a motor runs excessively hot and lacks power, it is on the verge of seizing. If you are on the road and don't have the right main jet, try raising the needle by lowering the clip. It won't be exact but at least you won't seize.
Note: To be certain that your problem is lean, pull on the choke and see if the problem gets better or worse. If better, your problem is a lean condition.
The following has worked for me: (Usual disclaimer about not taking responsibility for other peoples tuning (You silly Americans...))
Premise: A 2 stroke scooter with restricted CDI, a big bore kit (70cc) and a unrestricted exhaust and variator.
Start by lifting the carburator needle from the middle position to the top. Install a new main jet that is around 10-15% larger. It might need to be bigger depending on air box modifications Remember that with the stock carb it wont be able to suck that much more air and it is the ratio of air/fuel that matters. Start it up and listen to the sound and feel of the scooter. Re-jet as necessary.
With a original carburettor and a 70cc you should experience a good deal more torque, but should not expect higher top speed. That comes down to the ability to rev high - depending on the rev-limiter in the CDI and the air supply.
Personally I have never bothered with top speed. When my scooter does around 70km/h I'm happy with that and tunes for torque. In these cases it is not certain that a bigger carb will give value for money. It will certainly bring up the fuel consumption.
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Here follows a more detailed instruction on how to tune a carb by feel (following is not my work, but I have used this method for several years with great success):
You can only begin re-jetting your carburetor if the following conditions are met:
Top end is in good condition.
Bottom end is in good condition. Crank seals.
Spark plugs, air filters, reeds and so on.
If your bike's motor is not mechanically sound, then all the jetting in the world will not help. With all of the above conditions met, you should be able to jet your carburetor following these steps:
Step 1: DETERMINE THE CORRECT NEEDLE AND OR NEEDLE JET.
Whether or not your carburetor is a MIKUNI or a KEIHIN, it does not matter. This is the most important step in jetting your carburetor--period!
Remove the main jet.
Place needle clip in mid-position.
Start motor and run it on the stand.
Condition: Motor running and main jet out. Needle or needle jet is correct: Carburetor should run clean to approximately 3/4 throttle. From 3/4 throttle to full throttle, the motor should start to break up as a result of too rich condition.
Correction: None needed.
Condition: Needle or needle jet is too rich. Carburetor runs clean to approximately 1/2 throttle but breaks up before 3/4 throttle as a result of too rich condition.
Correction: Mikuni replace needle jet with next leaner and test again. Keihin replace needle with next leaner diameter and test again.
Condition: Needle or needle jet is too lean: Carburetor runs clean beyond 3/4 throttle and has an erratic throttle response.
Correction: Mikuni replace needle jet with next richer and test again. Keihin replace needle with next richer diameter and test again.
The emphasis here is to find the correct needle or needle jet diameter, which will allow more fuel to pass than is needed but not so much that the needle itself has no control below 3/4 throttle.
Step 2: DETERMINE THE CORRECT PILOT JET.
Make sure the bike is warmed up if at all possible.
Main jet out.
Needle clip in mid position.
Turn air screw all the way in then 1/4 turn out.
Start motor and run it on the stand.
Adjust idle so the bike will just barely idle.
Condition: Motor running and main jet out.
PILOT JET CORRECT:
With one hand on the throttle maintaining RPM at approximately 1/8 throttle, turn air screw 1/4 turn at a time clock wise until you bottom it out. Motor should become slightly erratic and you should have to play with throttle to maintain RPM. Start turning air screw counter clock wise, 1/4 turn at a time until you have reached 2 3/4 turns out. Between 1 1/4 and 2 1/4 turns, your motor should have reached its highest RPM maintaining a steady throttle. Adjust air screw again between 1 1/4 and 2 1/4 until you have determined highest RPM. Quick throttle response should be clean without bog.
PILOT JET TO RICH:
RPM does not reach a peak between 1 1/4 and 2 1/4 turns, stays the same or keeps rising out to 2 3/4 turns.
Correction: replace pilot jet with next leaner and test again.
PILOT JET TO LEAN:
RPM does not become erratic and motor maintains throttle when air screw is turned all the way clockwise.
Correction: Mikuni replace pilot jet with next richer and test again. Keihin replace pilot jet with next richer and test again. Remember, with a steady throttle approximately 1/8, there should be a distinct difference in RPM from 1 1/4 turns to 2 1/4 turns if the pilot jet is correct. The emphasis here is to find a pilot jet that will run crisp without bog and without the main jet.
Step 3: DETERMINE THE CORRECT MAIN JET.
The main jet selection process is easy once you have the correct needle diameter or needle jet. You now only have to correct a rich condition from 3/4 throttle on up and you know what a rich condition sounds like. Your pilot circuit is correct and without bog.
Replace main jet with one that is at least two sizes smaller.
Needle clip in mid position.
Start motor and run it on the stand.
By replacing the main jet with one that is too small, you are looking for a condition that is too lean. You adjust your main jet from a too small to lean condition.
Condition: Motor running and main jet in.
MAIN JET CORRECT:
Carburetor should run clean and crisp to full throttle.
Correction: None needed.
MAIN JET TOO RICH:
RPM reaches a peak slowly with a deep sound. Excess fuel and oil mixture at end of silencer. Spark plug fowls easily and is dark in color.
Correction: Mikuni replace main jet with next leaner and test again. Keihin replace main jet with next leaner and test again.
MAIN JET TOO LEAN:
RPM reaches a peak quickly but erratic. A quick full snap open of throttle causes the motor to hesitate. A BEWAH sound or a complete bog. Motor sounds like it has a ring to it. End of silencer white. Spark plug is white in color.
Correction: Replace main jet with next richer until the BEWAH bog just barely goes away, then replace the main jet with the next richer and run it. The emphasis here is find a main jet that is just rich enough to allow you snap the throttle wide open without the motor bogging as a result of the main being too lean. Should be a quick crisp throttle with no hesitation.
Jetting Tip: pilot jet and air screw
To check to see if your pilot jet and air screw are adjusted right, warm up the motor and let it idle as low as possible while still running smooth. From idle, whack the throttle wide open then let it close completely. Listen to the motor. If it bogs right when you whack the throttle open, then revs up, turn the air screw in 1/2 turn then try again. Do this until it revs up crisply. After the motor revs up, listen to it revving back down. If the revs drop quickly, and the motor starts to bog, and/or die, then you're too rich on the air screw, back it out 1/4 turn at a time. If after you let the throttle off the motor tends to run on and on while revving down very slowly, you're too lean and need to turn the air screw in 1/4 turn at a time. You want the revs to come up from idle quickly and smoothly, then drop back down to idle the same way. If you turn the air screw all the way in and it still needs to go further, then you will need a larger pilot jet. The opposite is also true: if you are backing the screw out so far that it darn near falls out, you will need a smaller pilot jet.
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This makes me even more excited to get his project started! Thanks!
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I have decided to install a BBK on my Like 50
It's difficult to get extra speed by installing a BBK & rejetting alone. The safest mod for extra speed is a BBK + gears. Gear sets that result in about 9:1 final drive ratio will give a nice speed increase with a 70cc BBK. The BBK gives the extra power needed to twist the lower ratio. Gears are cheap and easy to install. You only need to change 2 out of the 4 gears in the case. In some cases, cheap Honda Dio/Elite gear sets work. Even genuine aftermarket Kymco gears shouldn't cost more than $40-$50.
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Interesting...Im still in R&D regarding gears. Mostly because I do all my work on the sidewalk (City living!) and obviously dont have a shop press :(
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how the heck Im going to tune this thing once all the parts come in.
When upgrading a 2-stroke, just do one thing at a time as others here have suggested. The Kymco 2-strokes are similar to the Honda Dio, so I can suggest that you switch the jug but leave the stock carburetor except for changing the main jet from a #75 to a #90. You can add a tuned pipe at this stage, and 9:1 gears perhaps, but that's about it. Then ride it carefully for 500 miles or so to break it in, sticking to the original top speed. You'll have enough fun with the increased acceleration. The main problem with running 2-strokes at WOT is that (unlike 4-strokes) they can quickly overheat and melt the piston. Then you have to start all over again. This is NORMAL when tuning/racing 2-stroke scooters & dirt bikes. You're trying to go as fast as you can WITHOUT melting a hole in the piston. But sometimes you miscalculate. A Cylinder Head Temperature gauge is useful, more useful than plug chops.
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Joseph
I think you have a great point and I think that is what is best for me to do. When I have the engine out, do you think it would be OK upgrading the intake manifold but sticking the stock carb on it? Only reason I ask is because the engine is already off the bike and it would be so much easier to put it in at that time.
And if it is OK, will it let more air in despite being on the stock carb, perhaps upjet a little bit more to stay rich?
Muchos Gracias!
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do you think it would be OK upgrading the intake manifold but sticking the stock carb on it?
A bigger bore manifold won't make much difference. Similarly, a bigger carb won't make much difference if it's mated to a stock manifold. An upgraded manifold only makes sense if you upgrade the carb at the same time.
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Coolio!
Finally recieved my 70cc kit and Malossi Dell'orto phgb 19mm carb. Will install in approx 2 weeks. Current gameplan is to change the cylinder and intake manifold as I suspect it will be easier to change the manifold with the whole bike apart. I will break in the engine on the stock carb as I know how to tune it. Post break in the dell'orto will go on.
Luigi
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Installed the BBK this past weekend. Install went fine with 0 issues! The bike started right up on its first turnover. While I had everything apart I went ahead and installed the new intake manifold. I did not use the supplied carbon fiber reeds as another like owner on the forum stated all they did was cause trouble.
With the one change at a time mentality I have left the stock carb and airbox on the bike (for now) with no modifications except for going from 86 main jet to 95. I got the bike to idle although it idles really high right now (2600 rpm rather than 1850). In theory, how should the new bbk affect the idle and air screw settings relative to my previous set up? Not looking for exact turns but something along the likes of "the idle screw would come out and the air screw would go in". Should I go up an idle jet size? Currently it has a 35 IJ, I have 38 and 40 on hand.
I live in the city so I did all the work at my parents house over thanksgiving and they have kindly allowed me to leave it there. I tuned the bike so it could at least move without issue. Engine has been run ~1.5 hrs total in the 2000 - 6000 rpm range (varied). Im going to break in the engine as much as possible with the stock airbox and carb, then put on the dell'orto 19mm with holes in stock airbox, then finally open filter.
Its a work in progress....
For the interested some photos of the install
http://imgur.com/a/FbcOs (http://imgur.com/a/FbcOs)
Note after I put the new piston on the connecting rod I got so excited and forgot to take pics for the remainder of the install :)
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Current gameplan is to change the cylinder and intake manifold as I suspect it will be easier to change the manifold with the whole bike apart.
The intake manifold is easy to remove/change. It just takes 15 minutes with the seat pan out. I'm not sure if your new manifold will mate with the stock carb. If it doesn't match, don't sweat it, just put the stock manifold back. The hard part is ahead of you, trying to tune it so it doesn't overheat at WOT. Hint: add 10ml oil per litre of gas to the gas mix while running in your new cylinder. Try not to boot it for the next 500km or so. It's tempting, but resist the temptation :-)
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Already put in the new manifold and it was made by kymco so mated perfectly :)
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Over this xmas break I have had access to the scoot again. Theres about 2.5 hrs on the engine and maybe ~ 10 miles. Having trouble tuning the dang thing! Best Ive gotten with the stock carb (16mm) and airbox restrictor/collet out (no holes in airbox) is a constant 1500 rpm Idle. Id like to get it to 1850. I have gotten the "base idle" to be 1850 but is has a "secondary idle" at 2500rpm. Meaning if it idles at 1850 and i give a little 1/8 throttle rev the rpms will come down and "hang" at 2500 for a couple seconds then return to 1850. My 1500 rpm idle is clean and crisp.
I will place my 19mm carb on the bike once i feel the engine has broken in. Do you guys think having this tiny carb on it right now is preventing me from getting to my 1850 rpm goal?
For my 1500 rpm idle im at 2 7/8 turns out on the idle screw with a 38 pilot (1 step up) and 1 1/4 turns on the air screw. I have a 40 pilot in my possession too.
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I wanted too add that when the bike starts cold ie autochoke on, the bike idles at about 1900 just fine until it falls to 1500 one the bike is warm
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You have the hanging fast "secondary idle" when blipping the throttle, a symptom of a lean idle circuit. I think you may need to turn the air screw in a quarter or half turn more. Past that, you may need to swap a larger pilot jet in and start back again at 1.5 turns out. The ideal setting range is roughly between 1 and 2 turns.
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When upgrading a 2-stroke, just do one thing at a time as others here have suggested. The Kymco 2-strokes are similar to the Honda Dio, so I can suggest that you switch the jug but leave the stock carburetor except for changing the main jet from a #75 to a #90. You can add a tuned pipe at this stage, and 9:1 gears perhaps, but that's about it. Then ride it carefully for 500 miles or so to break it in, sticking to the original top speed. You'll have enough fun with the increased acceleration. The main problem with running 2-strokes at WOT is that (unlike 4-strokes) they can quickly overheat and melt the piston. Then you have to start all over again. This is NORMAL when tuning/racing 2-stroke scooters & dirt bikes. You're trying to go as fast as you can WITHOUT melting a hole in the piston. But sometimes you miscalculate. A Cylinder Head Temperature gauge is useful, more useful than plug chops.
Please dont take advice from this guy. Your engine is NOT a honda clone, it is more of a minarelli clone but not exact. It is in fact a HORIZONTAL not vertical engine style. The honda style is vertical (up and down not long ways) unless youre getting into super dio af35 styling and this engine is not that. Ive said it before and Ill say it again, if you dont know what youre talking about dont chime in with sage like advice thats incorrect and misleading.
Haarek gave you some great information and I would follow it.
thesurgeonistherobot is also correct in that your "secondary" idle is from a lean mixture, on the stock like carb the mixture screw is usually capped off thanks to EPA regs. You can drill a small hole and use a screw to remove it if it hasnt been done yet.
More than likely you have an air leak somewhere tho. I would lightly try to turn on the intake bolts and maybe the cylinder bolts, then check for a great connection to the carb. Always make sure to have a perfectly clean mating surface also when installing those intakes. I personally like CF reeds over fiber glass ones but I also change my reeds often.
Sounds like your like is on the way to being liked more!
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So I have in fact checked for air leaks and have found none. I have tried going in 1/4 turn on my stock carb (I removed the cap a couple months ago). I havent touched the bike since I last updated so now im starting to forgeth what I did. I do remember that the bike idles low (1500) and for the life of me cant get it to come up. Next time im home to work on it hopefully itll be warmer so its not acting so funny either.
FYI I have to stock carb (16mm) and stock airbox (no holes but intake collet is removed). Setup OK?
Love this new torque!
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I would just get the 19mm fitted and tuned rather than doing this tuning also. If no leaks and its hanging up then its pilot circuit is too lean and you have a larger pilot jet so you can just pop that in there and see how it goes. Also I clear out the cylinder in between pilot jet swap. Usually a good mid throttle running for 20-30 seconds will clear it out. Then as it idles back down I adjust the idle and mix. The Malossi cylinders like to flow some air for sure.
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Ya I have the 19mm carb sitting in the shed with the bike. No open air filter at the moment though. Maybe if I just go a head with that my woes will disappear.
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Please dont take advice from this guy. Your engine is NOT a honda clone, it is more of a minarelli clone but not exact.
Don't listen to this guy, he doesn't have a clue what he's talking about. You should never take advice from anyone who says they know it all like this blowhard does. As you can see, he's not even sure what kind of engine it is, so how can you trust anything he says? He's probably not even aware that you can use Honda Dio parts in most 50cc Kymcos, even the 4-stroke models.
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I do know what his engine is you turd :) its a mina clone, but not exactly a mina due to the slight upward degree of the cylinder. I also would like to make sure that he doesnt buy a single piece of honda parts for it since it is based off a yamaha design.
JJ is a moron, tried and true.
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Don't listen to this guy, he doesn't have a clue what he's talking about. You should never take advice from anyone who says they know it all like this blowhard does. As you can see, he's not even sure what kind of engine it is, so how can you trust anything he says? He's probably not even aware that you can use Honda Dio parts in most 50cc Kymcos, even the 4-stroke models.
Im going to guess this guy doesnt know me at all, do some research on what Ive done for this forum and others before you try to say anything. Im a Goliath of information. He just doesnt get that that engine in the like isnt at all a honda based engine. I currently have 2 like engines on my shelf right now. Oh wait is he going to put up another pic??? Oh wow he must not have them or Know anything about them since he has pics of them.
(http://i1305.photobucket.com/albums/s560/lovemy2strokes/Mobile%20Uploads/image_zpsf8cf7c3e.jpg) (http://s1305.photobucket.com/user/lovemy2strokes/media/Mobile%20Uploads/image_zpsf8cf7c3e.jpg.html)
(http://i1305.photobucket.com/albums/s560/lovemy2strokes/Mobile%20Uploads/image_zps2940e01d.jpg) (http://s1305.photobucket.com/user/lovemy2strokes/media/Mobile%20Uploads/image_zps2940e01d.jpg.html)
Heres a link to my photobucket so you can look at what a real deal scooter guy does.
http://s1305.photobucket.com/user/lovemy2strokes/library/?sort=3&page=1 (http://s1305.photobucket.com/user/lovemy2strokes/library/?sort=3&page=1)
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LoveMyKymco is a guru here...tried and true... ;)
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Wow..I'm excited for you too Luigi. How did the install go? I'm a newbie here and really starting to pick up a lot of interesting tips. I read somewhere else on this site about someone installing a bbk. How much did that kit cost you?
I'm in two minds at the moment. Tinker with my old Kymco or simply upgrading my bike to a newer one. It's really hard to find bits and pieces over here. Japan that is.
So have you installed the kit yet?
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Yes I installed by kit at the end of november. Basically I soaked up as much info as I could from here and other forums/resources. Then I watched the a 2 stroke bbk install video on youtube probably 10 or so times. Then went for it. Went without a hitch. She fired up first crank. Still working on tuning though. Ive only worked on the bike once since the initial install as its cold as hell here in Baltimore and I have no indoor work area. The bike is at my parents house about 2 hrs away. Ill probably bring it back up here beginning of March
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Heres a link to my photobucket so you can look at what a real deal scooter guy does.
This guy's an unbelievable blowhard who takes photos at the local repair shop and posts them while he boasts about what a clever and helpful guy he is. Don't trust anything he says. Anybody who doesn't know how to diagnose a simple 2-stroke has got to be a total pretender. How are you enjoying the dialog, LoveMyKymco?
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This guy's an unbelievable blowhard who takes photos at the local repair shop and posts them while he boasts about what a clever and helpful guy he is. Don't trust anything he says. Anybody who doesn't know how to diagnose a simple 2-stroke has got to be a total pretender. How are you enjoying the dialog, LoveMyKymco?
And you?
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I'm going to install the 19mm Dell'orto carb in hopes of alleviating my tuning issues, and maintain the stock airbox if possible. I have never installed a new carb before. The Malossi kit for kymco does come with a throttle cable. Do I need to use this one, or will I be able to use the throttle cable already going to the carburetor?
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This guy's an unbelievable blowhard who takes photos at the local repair shop and posts them while he boasts about what a clever and helpful guy he is. Don't trust anything he says. Anybody who doesn't know how to diagnose a simple 2-stroke has got to be a total pretender. How are you enjoying the dialog, LoveMyKymco?
Come to St Louis. Why would I take shots of someone elses shop when I own the building. Simple I dont need to argue I have real world proof.
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I'm going to install the 19mm Dell'orto carb in hopes of alleviating my tuning issues, and maintain the stock airbox if possible. I have never installed a new carb before. The Malossi kit for kymco does come with a throttle cable. Do I need to use this one, or will I be able to use the throttle cable already going to the carburetor?
You will need that cable as it will mate to the new Del carb and your splitter wire going to the old carb and the oil pump.
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Is this the carb you got? I run the Athena racing Del on a Piaggio LT50 Hi Per2 engine and a 94cc Polini evo kit. I have the PHBG19 del and the PHBL25 del. When I ran the 19 on a stock engine, W/oil pump, I found that the oil pump feed line on the PHBG to be too large and it causes the line to split. I would run new oil lines when doing this carb swap as their old and brittle.
(http://i1305.photobucket.com/albums/s560/lovemy2strokes/image_zps3d43a04d.jpg) (http://s1305.photobucket.com/user/lovemy2strokes/media/image_zps3d43a04d.jpg.html)
(http://i1305.photobucket.com/albums/s560/lovemy2strokes/image_zpsa6252bdb.jpg) (http://s1305.photobucket.com/user/lovemy2strokes/media/image_zpsa6252bdb.jpg.html)
(http://i1305.photobucket.com/albums/s560/lovemy2strokes/image_zpsf498a838.jpg) (http://s1305.photobucket.com/user/lovemy2strokes/media/image_zpsf498a838.jpg.html)
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Looks very similar based off my memory. I know the PHBG comes in several different models, I have the dell'orto PHBG 19 AS.
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AS is clamp style for the stock style intake kymco you bought it for thats the only difference. It should of came with a package with extra jets and a needle. Mine came with a W0 and W7 needle. The W7 was installed and I quickly changed it to the 0 but then went with a W3.
These are wicked accurate carbs but take a little time to fine tune. Not a lot of people on here have had good experiences tuning them as theyre not the same as Keihin or mikunis. You will need to do some reading for fine tuning with it as the jet and tune scale isnt the same.
What do I know, I havent actually owned or used one and I just took pics of someone elses stuff I guess. I also guess someone else paid my credit card invoice and ordered it to my house for me. Crazy world.
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Do you think I can keep my stock throttle cable or should I install the one that came with it?
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On the Piaggio Hi Per 2 it came stock with a dellorto carb so I could have used the cable or the stock one. Ill return on the 6th next week and if you havent set it up I can check at the shop then. A lot of people widdle down the stock cable ends to fit into the dels usually rather than go buy a new one.
I know I had to on my first del swap when I bought the wrong cable. If you order a single wire cable and using it on a del or arreche make sure to order a del cable, not a generic one or it will be for Keihin/mikuni style carbs. The only reason you would order a single cable conversion is if youre deleting the oil pump. On mina style based engines ( like the like) if youre not spinning 12k+ you can leave the pump and just add a 1oz 2 stroke oil to the tank full.
Being as its not a 100% correct and true minarelli design engine ( your engine is tilted at a degree not completely horizontal like a real mina is) I wouldnt try to rev it past 12k anyways. Real minas and morinis can spin way past 14k. At the point of hitting 13k rpms your stock pump cant meter enough oil because its already at its max vacuum draw. Thats why you need to add some to the tank. Problem is it will gum up your carb so you need to clean it every year or run some Seafoam every so many miles. I rather clean it every 6 months than run seafoam but I dont mind dropping the float bowl. On the PHBL style carbs the float bowl is held on by one screw in the center. Those rock.
Im only giving you 100% first hand experiences here, no speculation or reading someone elses posts online and regurgitating it. 100% field experience.
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Glad you mentioned the oil pump, I completley forgot there was a Y connection in there with the cables. I have the stock keihn carb so looks like ill be whittling down the end. At what point should you be adding oil to the tank (im assuming on top of what the oil pump is outputting too) with stock motor or as soon as you go 70cc? Also if I start adding 1 oz per tank do I need to play with jetting? Thanks for all the info.
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Add oil after installing the big bore kit if you are going to be running it higher than stock rpm. Always upjet with any introduction of pre mix. If you add something that isnt fuel (2 stroke oil pre mix) into the same size orifice(jet) youre no longer getting the same amount of fuel to the cylinder.
The main reason for more oil is for the higher rpms you will see with the better porting from the big bore kit than what the stock pump is made for. It actually makes less power on the extra oil you add but better safe than sorry if youre going to retain the stock pump.
At a side note also, the size of the cylinder also dictates if you need to add oil to the mixture as the volume is effectively larger. Not just higher rpms but displacement as well. Even if you were to keep it at lower RPMs if the cylinder volume is 50% larger you obviously need to compensate.
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The bike has a hose running from the oil pump and branching into a "Y" with one leg going to the intake manifold and the other leg going to the stock carb. The new dell'orto does not have a connection for this hose. Is the proper way to handle this on install is by replacing this hose with an unbranched, straight hose from oil pump to the intake manifold?
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Bump. Its the oil pump outlet line. I have no idea why it runs to the stock carb (Keihn PB16). Just a single line to the intake, right behind the reed valves should do the trick, amirite?
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Its the oil pump outlet line. I have no idea why it runs to the stock carb (Keihn PB16).
The oil line feeds a fitting at the PB16 slide and it lubes the slide; the surplus flows into the carb throat.
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Since that is not present on the Dell'Orto, I guess my proposed method is alright then
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If I'm not mistaken the new cable has a different end on it. That's why it's included in the kit. And it's a pain in the ass to get through the spring and into the slide.
Hope you get it running right. Pretty sure your idle issue will disappear with the larger carb. I hated the stock carb. Get your jets and needle right whatever you do.
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Alright Kymco-ers I need your help bad and asap!!
So Im finally home until this Saturday. Im trying to install the carb but I cant figure it out! The kit came with all the pieces in this photo
http://www.scooterworks.com/malossi-carburetor-phbg-19mm-pgo-genuine-kymco-50-2t-products-6971.php#.Uw-zpvldWzg (http://www.scooterworks.com/malossi-carburetor-phbg-19mm-pgo-genuine-kymco-50-2t-products-6971.php#.Uw-zpvldWzg)
except there is an additional bowden cable about 1ft long not shown for some reason. The current throttle cable set up is a throttle cable going from the handlebars to underneath the frame near where the battery compartment is. That is where the cable splits into two, one side to the oil pump and the other side to the stock carb. Both of the ends of the outer sheaths of cable are crimped onto their guides. This is ok for the oil pump but I cant free up the stock carb side.
Of course this Malossi kit comes with 0 instructions. I have no idea how to take apart the y connection where the single cable becomes one. I have no idea what Im doing with this dang kit!
Help??
Thanks!
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Doubted myself far too quickly :) :)
Figured it out! The cylinder where the throttle cable becomes was very hard to separate but i got it. The side with two cables separates after much force. After that I had to open up the throttle box on the handlebar to give me some more room in the cylinder. I removed the old carb cable and replaced it with the longer of the two in the kit. Now im gonna go put the carb on. Hope no more problems arise *crossed fingers*
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Carb install went fine. Im disappointed with the angle at which the throttle cable enters the carb. I purchased 90deg elbows but the cable doesnt have enough slack to accommodate them. Anyone know if its possible to get custom bowden cables done??
I put a 40PJ and a 95 MJ in. The bike started right up. Im on stock airbox with collett in. Will tune tomorrow.
Cheers KF, IM HAPPY AS HELL!
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Im having big trouble tuning this carb.
The PHBG carb is installed on the bike with the 70cc Malossi kit and 100% unmodified airbox (read: no holes)
Current jetting is 35 IJ and 92 MJ
Can anyone share their jetting setup for 70cc and PHBG along with airbox mods so I can have some starting point?
Gracias
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I HAVE GOOD NEWS (I am talking to myself at this point!)
I got this sucker dialed in!
35 IJ was wayy to lean. The correct IJ is 42 WITH the airbox restriction OUT.
Currently have a 96 MJ in but I think its tad lean so Im going to bump it up to 100 or 102 then start pluggus choppus (source Wassonii).
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A more efficient way of tuning is with a wide band egt, if no wide band use a TTO head temp sensor by trailtech. The Trailtech tto goes for 36-50$ and worth every penny while tuning and after. Plug chops are great but they only let you know well after the fact of whats going on.
Best of luck and keep on goin!
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Thanks LoveMyKymco.
I actually bumped my Main Jet to 102 where I lost some performance compared to the 98 jet (I misread the 98 jet as 96).
Ill stick around there for the time being. I also have zip tied the oil pump open.
Now I got a question about tranny gears. It is possible to pull out the gear with the shaft that attaches to the clutch (i guess the input gear) out of the left case without using a press or having to pull the whole dang engine out?? (I JUST DID THAT!)
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I use a tusk puller to pull the primary gear rather than pressing them, the problem lies with the counter gear if it is pressed or not. If its pressed you have to bring it somewhere if you dont have one.
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Ok Ive done some research on the EGT and Temp sensor. Im not trying to put any holes in my exhaust pipe so the egt is out. I like the trail tech.
Whats the general process for tuning using the temp sensor?
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It will tell you when your temps rise to a level where its unsafe. Anything above 400 can damage your engine, I stay around 350. The higher the temp the leaner your engine is. If it never reaches 325 then youre way too rich.anything between 325 and 375 is great. 325 is the bare minimum and you should shoot for 350-370 cruising, 375 max downhill.
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Great!
....now I got a temp gauge on my wishlist:)
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Update I received the Temp guage but have not installed it yet. I have also acquired the malossi upgeared final drive and malossi vari along with rollers/springs etc. All off the bike for now.
Break in is going awesome. Little did I know the BBK gave my bike wings :)
Now for a question, does the adjustment screw on the PHBG adjust air or fuel? When I turn it in am I directly reducing air or fuel? Grazie Scooter Heads