Thread: 80cc Mystery
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Old 06-24-2008, 01:50 AM
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Egor Egor is offline
Motorized Bicycle Elite Member
Join Date: Jan 2008
Location: Hurricane Utah
Posts: 714
Default Re: 80cc Mystery

That is an ignition problem, not with the fuel. If you are willing to do a simple check. Take the plug cap off put the wire on the plug and start the engine now have someone else turn the throttle and as they do pull the plug wire just enough away from the top of the plug to watch the spark. As you run the engine you will see it cut off and on. The reason I told you to get help to do this is you need to keep your hands off the bike so that if you pull it too far away it will not bite you. If you have an intermittent spark I would blame the coil first. There is a chance you can use some cold shot and spray the coil with it and chill it down, it will start to run when cold, sometimes. That is an indicator. I have had many motorcycles with that problem. Rich and lean refer to the amount of fuel you are delivering, you can't change the amount air. Your piston is washed, so it is rich from not com-busting, the result of bad spark. Have fun, Dave

PS: If you don't have the courage to hold the wire away take a piece of clear fuel line and put it over the end of the wire, next slip the tube over the end of the plug, get the wire close to the plug and start the engine, you can look through the tubing and watch the spark.
I will add another PS: Take the kill wire off before you do anything, they are junk.
Its just a job. (Link) My shop is in the lower R/H corner.

Last edited by Egor; 06-24-2008 at 11:58 PM.
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