KymcoForum.com
Scooters - 50cc => Agility 50 => Topic started by: wordslinger on September 07, 2009, 08:52:04 PM
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..just ordered a K&N RC-2290 air filter ($40.00) for my scoot, to upgrade from the original stock filter..
..should I anticipate a jet modification for proper carburetor tuning?..
peace
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..just ordered a K&N RC-2290 air filter ($40.00) for my scoot, to upgrade from the original stock filter..
..should I anticipate a jet modification for proper carburetor tuning?..
peace
I had it on my Kawasaki ZR-7S (750 cc), together with carb re-jetting and new slip on.
I think you will get answer to your question after you install K&N, not before...
Is it "open" type of filter? If so, your carb will probably need more fuel.
If it is just replacement type of filter, then probably no change is needed.
Considering that your Agility is 4-stroke, they are less sensitive to changes in air filter configuration compared to 2-stroke bikes so I think you will do just fine with your current setting.
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...looks like this one..
..I'm betting that I will need to re-jet..
..but, hey..that's not a bad thing...maybe a little more power...
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It made a huge difference on mine. I tried the stock air box after I did my 70cc kit and it would barely run. I drilled some holes in the air box hoping that would help and I was still not getting enough air. All is well with the K&N! I did end up having to run a much bigger jet than I had started with though! I was trying it with a 90 at first and ended up with a 115. You won't know for sure till you get it installed, but i would anticipate having to up-jet. Make sure you don't run it lean!
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This is "open" type and probably you will need to add more fuel to the mixture.
...looks like this one..
..I'm betting that I will need to re-jet..
..but, hey..that's not a bad thing...maybe a little more power...
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Make sure you don't run it lean!
..how can I tell if I'm running lean?
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Make sure you don't run it lean!
..how can I tell if I'm running lean?
Burnt (hole in a) piston. :)
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Burnt (hole in a) piston. :)
...umm..yeah... ???
..any way to tell before it get's that far??...
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Do a WOT plug chop after you install the filter. You may be able to get away with just adjusting the mixture screw. Play around with that before you start messing with the jets.
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Do a WOT plug chop after you install the filter. You may be able to get away with just adjusting the mixture screw. Play around with that before you start messing with the jets.
...wots a WOT plug chop...
:o
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Hey!
I am being quoted here!
Too much air will burn away white insulation around central electrode and corrode the main electrode too.
http://image.superstreetonline.com/f/8999501/130_0703_03_z+reading_spark_plugs+lean_spark_plug.jpg (http://image.superstreetonline.com/f/8999501/130_0703_03_z+reading_spark_plugs+lean_spark_plug.jpg)
Also if your exhaust pipe is white-ish inside instead of black, it could be a sign it is running lean.
Finally, do not check that until engine is warmed up because cold engines usually run lean as more air is getting inside due to choke action.
p.s. Here we have probes at technical inspection station they shove up your scooter's/car's ass and measure exhaust for CO, CO2, NO2, SO2 etc... if you know somebody there you could try asking them to help you...
..axy, how long should I run before I would start to see the white deposits in my exhaust...
..I don't want to damage my piston..
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...wots a WOT plug chop...
:o
..OK, I did a little research for myself, and found the info on the WOT plug chop...
;D
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You should be all good then! Happy tuning! ;D
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...installed...tuning in process...
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...need more fuel...
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..i like this look...ugly air box is history..
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..okay, so I'm at a @ 102 jet now...that's 1.02mm, or @ .040" for all of us on this side of the pond...
..initially, I had to wrap my filter to maintain 3/4 throttle...
..raised my needle @ .060" and I can maintain 3/4 throttle without any wrap on the filter..
..still can't go to full throttle without bogging down, kinda like the engine tries to brake..
..I never imagined such an increase in the main jet's size..Does this sound normal??
..I think I need to increase the main jet size even more..Does that sound correct?
peace
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..okay, so I'm at a @ 102 jet now...that's 1.02mm, or @ .040" for all of us on this side of the pond...
..initially, I had to wrap my filter to maintain 3/4 throttle...
..raised my needle @ .060" and I can maintain 3/4 throttle without any wrap on the filter..
..still can't go to full throttle without bogging down, kinda like the engine tries to brake..
..I never imagined such an increase in the main jet's size..Does this sound normal??
..I think I need to increase the main jet size even more..Does that sound correct?
peace
When are you back on 4 wheels? :)
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When are you back on 4 wheels? :)
...December i believe...why??
???
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If it will run at all at full throttle try and do a plug chop. Just don't run it for more than maybe 1/2 mile at WOT. You don't want to do any damage if it is running lean. That should be enough to get some color on a new plug. Remember to use your kill switch while still maintaining WOT. Hold the throttle until you come to a stop. You may be running rich as well, I saw the same symptoms running a 130 jet on mine, but I have a 70cc. Though, I wouldn't be suprised if you needed to go a little bigger. Goes to shows how restrictive those stock air boxes really are! ;)
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If it will run at all at full throttle try and do a plug chop. Just don't run it for more than maybe 1/2 mile at WOT. You don't want to do any damage if it is running lean. That should be enough to get some color on a new plug. Remember to use your kill switch while still maintaining WOT. Hold the throttle until you come to a stop. You may be running rich as well, I saw the same symptoms running a 130 jet on mine, but I have a 70cc. Though, I wouldn't be suprised if you needed to go a little bigger. Goes to shows how restrictive those stock air boxes really are! ;)
I'm amazed...yeah I can run at full throttle, however the only difference is, the throaty sound coming from the filter..no increase in actual engine output...
..i'll try the plug chop...
..how long would it take to do damage???
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Mine made that throaty noise also when it was both too lean and too rich. I'm not sure how long it would take to do damage. I guess it depends on how "off" it is. I wouldn't want to push it though. I have a nice straight road about 1/2 mi long out of my neighborhood that i ran down for testing mine. Seems to be about long enough to just get some color down around the electrode of a new plug. I just pop in a new plug and run it out to the end of the road. Kill it and pop in the regular plug to run back home and examine the other plug.
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..and you're sure that it would not be abnormal to have to increase my jet size even more?
:)
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Not totally sure. That's why I would do the plug chop to check and see where you are at. Did you increase the size in smaller increments, or just go right to the 102? Typically you only want to move in either direction a difference on 5 at a time. If you jumped straight from 85 to 102 then you very well could have just skipped over the "ideal" and made it too rich! If you went staight to 102 then i think you may have gone too big because 15 should make a noticable difference. Ideally you would want to try the 85. . . 90. . . 95. . . and also do a plug chop with each new jet. I think I have a lifetime supply of "only used 1/2 mile" spark plugs at this point! ;D
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..i did go incrementally...the bigger I got, the better it performed...
..did not chop at each point though...
..imma go chop a plug..not sure if I'll get to update any more today..
..thanx, Shaka, and everybody else for ya'lls help!!
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Ok, good! Then it sounds like you're moving in the right direction! I wouldn't be too concerned that you are having to run an unusually large jet. It is what it is! I am running a 115. Mine is a 70cc, but also a larger diameter carb which should compensate for the engine size difference.
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I just installed a K&N filter too. ive got a 70cc kit installed but the carb and exhaust are stock. when I get to about half throttle the engine begins getting loud and continues all the way to full throttle...ive got a #95 jet in the carb right now. It doesnt have much power compared to when I had the stock air box on with #85 jet installed. Could it be running too rich?
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Tutto- The only way to tell is the plug chop. I would definately do one! I would think you are running lean using a 70cc with the stock carb! Only one way to tell though! ;)
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I decided to try a 90 jet and the scooter wouldnt go past 30mph..and there was white smoke coming out of the exhaust.
I also plugged the breather line on the head cap cause I didnt know what else to do with it and it blew off when i was running the engine.
guess Ill try a plug chop
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White smoke coming out of the exhaust isn't a good sign! Sounds like you are definately running lean!
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for my little stand on scooter and my nitro RC cars white smoke is a sign of running too rich. I think what was happening is... because I plugged the breather line some oil and gas were coming through the exhaust pipe.
I tested it again with the 95 jet and its bogs for half seconds at a time.
I guess I need like 100 or 105 jet?
Once I get this straightened out im done messing with my scooter. Im ready to move up. I plan on getting a sports bike soon like a Ninja 250r, 650r or a used R6 is I can afford it.
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I'm not certain but I heard somewhere in regards to a 2-stroke; white smoke is too lean, dark smoke is too rich, and blue smoke is oil. I'm not sure if all of that applies to a 4-stroke also.
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..okay, here's where I think I went wrong...Initially, after installing my filter..
..Did Not perform plug chops...
..assumed that the reason I had no throttle response through 1/4-3/4 was because the main jet was too small..
..continued to increase main jet size..when in fact, I should have raised my needle...
..raised the needle, and have throttle thru 1/4-3/4... however, my main jet is now too large...
..WOT plug chop showed black deposits..I can smell gas fumes when I never could before...
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I think you got it figured out. The main jet size only affects WOT. You can do plug chops at other throttle positions besides just WOT. I found the best way to do that is to wrap some tape around the throttle and mark off idle and full throttle then split the the difference till you break up the space into 1/4's. That way you can be sure you are holding the throttle in the right position. I hope you have another jet to drill out! Good luck!
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...woooo-frickin-hoooo!!!
..102 jet...needle in it's original position...
...I'm pegging the speedometer...
..the sound the K&N gave my scoot is awesome too!!!
..more pep...more flat road power...
..I couldn't have done it without you guy's help...
;D
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Good News! Good News! ;D
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for my little stand on scooter and my nitro RC cars white smoke is a sign of running too rich. I think what was happening is... because I plugged the breather line some oil and gas were coming through the exhaust pipe.
I tested it again with the 95 jet and its bogs for half seconds at a time.
I guess I need like 100 or 105 jet?
Once I get this straightened out im done messing with my scooter. Im ready to move up. I plan on getting a sports bike soon like a Ninja 250r, 650r or a used R6 is I can afford it.
..tutto...from my recent experience, I found that black smoke indicates a "RICH" condition...white smoke means you're running LEAN...
..DON"T RUN LEAN!!!
..I think axy went to a 115 with his 70 kit...
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Glad to hear slinger! ;D
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Now there is a class in carb tuning. Tutto has a problem w/ the plug he put in the breather you can use a small filter to replace the hose that belongs there. The hose will soften with time and not want to stay there. YOU MUST have that port OPEN to the outside. It equalizes preasure from the cylinder blowby, and the outside air. If the port is blocked it will preasurize the crankcase to the point of blowing seals/ gaskets. The white smoke could either be oil (probally forcing past the valve seals), or coolant (from the head gasket) if it's oil the plug will be black, if coolant the plug is white. Either way get a breather back on there.
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Now there is a class in carb tuning. Tutto has a problem w/ the plug he put in the breather you can use a small filter to replace the hose that belongs there. The hose will soften with time and not want to stay there. YOU MUST have that port OPEN to the outside. It equalizes preasure from the cylinder blowby, and the outside air. If the port is blocked it will preasurize the crankcase to the point of blowing seals/ gaskets. The white smoke could either be oil (probally forcing past the valve seals), or coolant (from the head gasket) if it's oil the plug will be black, if coolant the plug is white. Either way get a breather back on there.
..ok, cool..that answers what was goin to be my next question, since I removed the stock airbox...so far i had just been letting that hose hang...
..it needs a breather on it...
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yeah, I immediately unplugged the breather line and popped a small filter on it
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Cool, Your smoke should stop, if it was oil getting past the valves. I would still check the plug to verify. It's AWESOME to see scoots coming together. Hey slinger I would DEFF. suggest you try the same. A small filter will keep debris from entering while allowing the preasure to escape. Maybe tuto has a source! And thanks for the email it made my day
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Cool, Your smoke should stop, if it was oil getting past the valves. I would still check the plug to verify. It's AWESOME to see scoots coming together. Hey slinger I would DEFF. suggest you try the same. A small filter will keep debris from entering while allowing the preasure to escape. Maybe tuto has a source! And thanks for the email it made my day
Yeah, imma get me one...I have a cool little brass muffler i'm going to adapt to the port..
..just got the tube tied up in a safe location right now...
..It's good to see this forum lite up a bit!!
..
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Hi, I'm using K&N filter about 1 year (and about 3500 miles), and here are results:
I had to upgrade to .88 jet (stock was .78, I tried .82 and it didn't work) and do some minor carburetor adjustments, scooter is much much louder, but loudness decreases with time (as filter gets clogged from dust), filter is screwed directly on carburetor.
K&N filter increased acceleration and noise level, top speed wasn't affected by mod.
It's cheap mod and it helps, stock air filter has a very low air flow when compared to K&N
Scoot is
agility 50, '07, (6.2g rollers, Vespa ET4 variator belt, K&N with .88 main jet, unrestricted CDI, scooter has done 12000 miles)
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Most of my experience is with the Chinese GY6 and Im assuming these Kymco setups are a bit different.
Setups I use for the Chinese 50cc GY6
50cc GY6 Free Flow Airfilter 88 main (I think this setup runs just a tad rich)
50cc GY6 Free Flow Airfilter & Exhaust 90 main
72cc GY6 and Free Flow Airfilter 88 main
72cc GY6, Free Flow Airfilter, and Exhaust 95 main
I have never had to tune past a 95 main jet except on my drag race scooter, its running a 102 main. It has 85cc, velocity stack, port & polished performance head, cam, exhaust, 19mm carburetor, lightened rocker arms, lightened valves, ect. Never have had it on the track yet but I can tell you its as fast as a stock 150cc off the line and would hang up to about a 1/8 mile then I run out of gear.
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The gy6 is pretty much a dead ringer for the kymco 4t set up! Having those guide lines posted will most certainly help, if people can find the post. The trouble I see most often is in people finding advice such as yours, and shopping the "clone" sites. Thats where the problems begin for most. The fella I bought my zx/super fever from is a very talented scooter enthusiast so I had a jump start on which parts to buy. Just had to shop around for price! It sounds to me like you (Dr.Moto) have some talent as well. While I DO NOT want to attempt to speak for anyone, I believe your experience, and parts knowledge can benefit allot of people looking for help here. At the moment my scoot is pretty well set up, but I am looking around for a project super 9 to set up in a more "full race" fashion. Anyone that sets up a "drag" scoot is someone I will be looking to for advice/ opinions. Sorry for the Hi-jack... PLEEEEAAASSE stick around!
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Much agreed, definitely an asset! We could use more of those around here! Any advice on final reduction gears and/or reed valves would be appreciated! Check out my thread under zx50. Please stick around!
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Not a problem 8)
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Most of my experience is with the Chinese GY6 and Im assuming these Kymco setups are a bit different.
Setups I use for the Chinese 50cc GY6
50cc GY6 Free Flow Airfilter 88 main (I think this setup runs just a tad rich)
50cc GY6 Free Flow Airfilter & Exhaust 90 main
72cc GY6 and Free Flow Airfilter 88 main
72cc GY6, Free Flow Airfilter, and Exhaust 95 main
I have never had to tune past a 95 main jet except on my drag race scooter, its running a 102 main. It has 85cc, velocity stack, port & polished performance head, cam, exhaust, 19mm carburetor, lightened rocker arms, lightened valves, ect. Never have had it on the track yet but I can tell you its as fast as a stock 150cc off the line and would hang up to about a 1/8 mile then I run out of gear.
...this is all very interesting to me...as I have a 105 (1.05mm) main jet in my A50..with a free-flow filter..stock exhaust...and find that it seems to be lean in cold weather..less than 40 degrees F...hmmm....
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They will ALL run leaner in colder "denser" air. Those bordering on the rich side (in warm conditions) will tend to run better than those on the lean side. All the jet sizes are relative to the manufacturer anyway. Mine gets pretty "snappy" on the colder mornings. More like a cracking whip than a purring tiger!
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These settings are on the Chinese carburetors so it may be different. However I use a 115 main jet on a 150cc scooter with a free flow airfilter and exhaust for reference.