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Old 10-14-2008, 07:46 PM
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jerseykat1 jerseykat1 is offline
Motorized Bicycle Elite Member
Join Date: Sep 2008
Location: North Plainfield, NJ
Posts: 134
Default Re: i think my "80cc" has issues. top speed only 28mph with shifter kit...

Originally Posted by Norman View Post
stock main jet is around 0.070 mm My engines run the best on 0.065mm main jets.
check your needle for taper I think it should start out by the clip grooves at 0.070 and taper down to 0.065 those numbers might not be right but if you can mic your needle it needs to have a taper. Pablo had one that didn't have the proper taper and it would not rev up at all I worked on it and got it to working good on my bike then I shipped it back to him I guess he either shelved it or put it on his bike.
If you want I can have you send me your carb and I'll test it on my bike and see if i can do some mods to get it to perform all you need to do is pay for the shipping. I have 70cc and the cough, cough, 80cc engines to test it on.
Thank you norman for extending your servies, i really appreciate it. But i am happy and ashamed to announce that i have solved the problem. It was a simple and stupid mistake on my part. when i installed the shift kit (by the way this thing makes my bike a freakin rocket havnt recorded top speed yet as its too dark out right now and i cant see the speedo but it flies now) my engine had to be slightly relocated and such forced me to remove the filter housing, shorten the screws that secured it, and bolt that honey combed shaped thing directly on top of the crappy little foam tpype filter. well that put it too close to the intake port and i guess at higher rpm it was just not getting enough air because of how close the foam was to the opening (i feel like an idiot goat herder hit the nail on the head when he said "these ch engines really need to breath"). So to remedy this i used some nylon front door screen (yes the kind used to keep bugs out your house) folded over about 4 times, used my Dremel to remove the plastic sections that are directly over the carb port, and installed it in the same manner. Problem solved and it should provide about the same filtration as that crappy foam filter. maybe i will play around with difrent materials tomorrow. below is a picture of the carb with mt revised "fit in a tight spot filter" the valve sticking out of the intake manifold is something i created to try and adjust A/F ratio it works well i will try and fine tune it tomorrow. Can't wait!!

Last edited by jerseykat1; 10-14-2008 at 07:54 PM.
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