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Old 04-11-2014, 07:07 PM
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Henshooter Henshooter is offline
Motorized Bicycle Elite Member
Join Date: Feb 2014
Location: Melbourne au
Posts: 278
Default Intermittent 4 stroking

Hi guys I'll start with the running specs of my motor and then get to the problem .

Standard 66cc chinagirl kit with angle fire head and speed carby (the one with the red air filter) ,replaced standard CDI cable with good automotive one , kit has run for approx 2 months . Full flushed fuel system and it's as clean as a whistle so no issue with fuel , changed from 16:1 kit recommended to 32:1 fuel mix , no contamination issues .
about 2weeks ago I had issues where she would stall out constantly ,turns out it was an issue with crap in the tank preventing proper fuel flow ,I've since rectified this by giving the whole system a full flush ,later it had a spontaneous issue with fuel leaking from the bowl ,reseated the bowl seal and slightly bent the brass tang arms to lower the level of fuel in the bowl and changed the float out ,checked the jet and she's as clean as .

Now I did a chop test and it indicated she was running slightly lean , so I moved the needle down a notch and it seemed to improve the running of the motor for a few days ,but now she is constantly 4 stroking intermittently at either middle or top end ,I can actually feel her lose power at top end and 4 stroke ,I'll release the throttle and she will fire up as normal but it's like she runs well for a few seconds and then 4 strokes ,then runs normal ,I've made every adjustment to fine tune the carby but one way she runs lean the other she 4 strokes .

I'm at a loss as to what steps to take to get her running like normal again
Is it normal for the motor to 4 stroke occasionally or is there something I can do to resolve this issue ie is it ok to run her ever so slightly lean ,it's not like she is running overly lean just a very slight white haze on the plug

Help I'm lost
Regards Henshooter
Light travels faster than sound ,ergo some may appear smart until you hear them speak
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