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Scooters - 50cc => zx50 => Topic started by: LoveMyKymco on May 12, 2012, 07:00:59 AM
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I know a couple people have run this set up, what jetting did you use? Im running MHR bbk running 32 :1 premix, 38 pilot 122 main, with a CT mani, 24mm OKO(power jet blocked off), UNI open filter, Motorio expansion chamber, unrestricted CDI, "performance" coil.
At idle it will die unless I give it some throttle, I even set my idle to 3600 and still bogging out, the clip setting is in the middle so I will lower it tomorrow. I started with a 44 pilot, then 42, then 38, still bogey at lower than 6k rpm ( I associate it with the pipe) maybe I need to go even lower on the pilot? I kind of dont want to though as Im breakin it in. It will run great with the choke on at idle which makes me think too large of pilot, but its only a 38.
It sucks to not be able to see what this bad dog has, even 1/4 throttle from a stop will pull the wheel for a sec, tryin to be nice during break in sucks. Im using a malossi variator with 7g polini weights, SEF ramp, naruku high speed pulley,polini racing clutch with 2k springs, 1.5k malossi spring. I have the malossi primary gears to put in after break in is done. Near a full tank ran through it today. After tomorrow at the park teaching my girl friend how to ride itll be ready. I guarantee she wont floor it, ha.
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Moved it back to a 45 pilot, not a 44 duh. And set the clip to middle works like a charm. Some reason I thought it was too rich. This is a serious monster for only 72cc. Im done with heat cycling and break in, and going to take it easy for the night, but tomorrow Im going to tear it a new A hole. After 5 hours of break in and heat cycles, Im pretty ready.
So for a extremely ported intake passage, ported CT manifold, 24mm OKO with UNI, Boost port matched block, motorio or expansion chamber set for high 8k rpm+ seems 45 pilot and 122 main works well. From a stop if I give it any kind of real throttle it will lift the front wheel and I came close to 12 o clocking the ride a couple times, I cant imagine flooring it.
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122 was too lean or I have an air leak, Im getting it to the machine shop to have it pressure tested for fun before we bore the case for a stroker crank and bore this MHR top end out to 47.5mm. Im going to go with a 125cc 54mm TieJuan and 52.6mm Ruima crank with a big CT mani and 28mm carb. I think Im going to order 2 bore kits, just in case.
I have a 50mm BBK that has a K and H on it, no clue where its from but its casting looks like sh**. More than likely not going to use that one. Well see.
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One of the Skirts broke of on the ruima jug. It haeneed in my hand. One more minuite of riding would have trashed everything.
If it looks cheap... Trash it.
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Here at 2225ft i was using a 125mj--45pj in my oko...
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It kept trying for 11k rpms, always between 9200-10.5. It would seem that the pipe I have is good for after 8500 for sure. When it hit powerband it was like opening a 4 barrel. My friend said it was trying to lean out too much and thats why it was hitting that high rpm so easily.
Its the first time Ive melted a piston that fast, it was kinda fun until loss of compression. Lesson learned, Im going to start off fat on the main jet next time and not try for perfect tune first try. I just hate taking sh** off to get to my carbie. Im tempted to cut my panel a little.
This 50mm jug doesnt have a name or any marking except for a H and K. Not really alot of choices when going big stroker it seems. Im installing the 50 on one of my elites tomorrow after i finish this chambfering and the hone arrives. Ive ported 7 jugs this weekend and my burr bit is less burry, back to sears for another one before I finish these. I practiced on the junk ones I had laying around. When I come back through with the flex hone should I use the 240 or the 320 grit one? I ordered 2, 1 7/8"s and 2, 2"s, 240 and 320 grits. I also ordered a nikasil one.
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I will ASSUME the pipe you have is the same one i installed on a cobra awhile back since you did say it was a Motorio... I had no problem getting the rpm's up there with that pipe. I did not fully try and tune to the pipe of course. I could hit 10g's on the oem tach. (i have the trialtech tto tach on MY scoots).
I hate to hear that you melted one tho. That way sux. >:(
You should be able to get to the carb FAIRLY easy even with the panel on. 1 hand up top, 1 hand below. I usually leave the panels off for a day or so. ride naked. ;).... Yeah, if i was running a 125mj you should try a 132-135mj. I do have a set of the needles for the OKO but have never tried tuning with them. BE CAREFUL WITH THE NEEDLE CLIP. IF ANY LOOSENESS AT ALL, IT WILL COME OFF WHILE RIDING. IDK if Shaka remembers that ordeal i had or not but my clip just came off.....MULTIPLE TIMES. I was out riding like always and BAM....The needle would fall down and i thought my engine was all f'd up.. :D....Not saying it WILL, but it dam sure can.
I was running 125mj----45pj----needle in the 2nd slot----mix @ 1-1-1/2 out @ 1950-2225ft above sea level.
Also be careful of vibration now. These lil f'rs will vibrate like a mo fo. ;) Personally i think that part is awesome but can be a PITA. Nuts, bolts become loose easier now as well. Pay close attention to your exhaust. The vibration will kill around the 1st bend from the header. Mine was vibrating bad before ;) but now with a mini-stroker, she really pounds. 8)..........or was, got me some gear damage............STILL >:( :'(
I do believe i have the 320 grit flex-hones and they work just fine ;). The 240 may be pretty rough just for a cleaning since the 320 does great with a lil WD-40....
I also ordered a nikasil one.
A what? a Nikasal flex-hone?.. ....SUPPOSEDLY you better not use a flex-hone on a Nikasil bore..... I do wonder if it really does hurt, BUT it is a coating. :-\
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The max rpm's you can get are set in the jug's timing. If you want higher rpm's you have to lower the deck, of raise the ports. That is all pre set stuff. The Flex hones, are good for major removal but ball hones are much better for clean up work. I use a 400gr ball hone on every new install, as well as de-glazing any type cylinder. As of right now I have a 52 pilot in my OKO 24, and don't know what main is in it(72cc Corsa). The 50mm I was running used a 44 pilot, and 135 main if I remember right.
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??? ???
The Flex hones, are good for major removal but ball hones are much better for clean up work.
Hmm, i thought they were one in the same....flex-hone--ball-hone--dingleberry-hone..
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??? ???
The Flex hones, are good for major removal but ball hones are much better for clean up work.
Hmm, i thought they were one in the same....flex-hone--ball-hone--dingleberry-hone..
So did I. ::) I personally use a somewhat custom hone I made from 2 different ones. It has 3 straight stones that are spring loaded outwards. I don't like using the flex/ball/dingleberry hones in 2t's, they can easily get caught in the ports.
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I call the blade type hones "flex hones". I may be wrong on their real name.
http://www.bikebandit.com/ammco-cylinder-hone-replacement-stone?WT.mc_id=1484958&CAWELAID=549989282&gclid=CODd6Oy4kLACFQiynQodyxCkoQ (http://www.bikebandit.com/ammco-cylinder-hone-replacement-stone?WT.mc_id=1484958&CAWELAID=549989282&gclid=CODd6Oy4kLACFQiynQodyxCkoQ)
Yep! I just googled flex hone, and a ball hone came up!
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Yep...that's the kind I use. I took the holder/arm part from a car master cylinder one and replaced them with some long stones from a car cylinder hone. It doesn't quite fit in a stock 39mm bore...but I don't really mess with those anyways! ;D
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I don't like using the flex/ball/dingleberry hones in 2t's, they can easily get caught in the ports.
???
I musta missed something... They seem to help champher the ports IMO..
The blade style can catch the port and chip sh** off IMO...... well if the smaller "brake-hone" could. I've caught them before myself
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They may help chamfer the edges on a steel cylinder...still iffy IMHO. I made it for a Nikasil cylinder which chips very easy. Yes, the small brake one does easily catch in the ports. That's why I modified it with 6" long stones.
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I made it for a Nikasil cylinder which chips very easy.
I was under the impression that you could NOT use a hone on an alum cyl......
I be dam.. I have an airsal kit that was supposedly bad....IDK HOW tho.. I cleaned it with a hone, looks good now but i never found any verification about alum
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That coating is pretty darn tough. As long as you don't chip it it's all good. All the hone does is remove any aluminum and such from the piston. I honed mine twice with no issues.
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That coating is pretty darn tough. As long as you don't chip it it's all good. All the hone does is remove any aluminum and such from the piston. I honed mine twice with no issues.
No sh**?... WOW. Yeah, i think it just had a bit of alum from a piston on it. Light scoring. The ball hone made it look good to me.... Dam, i wish i had a piston kit... :D (it's for a l.c. s9)..(the piston kits are like $65-68 tho.... for an airsal anyway).. be an expensive try and hope... :D ::)
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Yep...I replace my piston and rings every 100 hrs so that was more or less routine maintenance. I didn't want to risk a failure in that plated cylinder.
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I may have some hope to get my s9 back up finally.....
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http://www.usnicom.com/ (http://www.usnicom.com/)
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http://www.usnicom.com/ (http://www.usnicom.com/)
Not worth it on these Airsal cylinders. That place is $198 to strip and re-plate...A new cylinder kit is $168 for AC and $230 for LC from MHR. They are currently out of stock, but just saying.
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:'( :'( :'( :'( :'( :'( :'(