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Q: Moped Engine Question

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Good Day,

This should be very easy for you guys.

It's regarding my Tomos 49cc (2 cycle) moped engine. Moped had to sit awhile because I messed up the clutch. So a year later I replaced the clutch and then it wouldn't start.

When it does start after a long rest period - It idles kind of high gives VERY SMOKEY and thick exhaust (some in liquid form) - then shuts off. And after that it won't even crank on again. That's it..


Hi There, It sounds like your moped engine is fouling the spark plug as a result of a a rich oil/fuel mixture. As you know, 2 cycle engines mix fuel and oil together in the fuel tank which is run through the motor. The oil in the fuel helps to lubricate and cool the motor, however these types of engines are prone to fouling spark plugs when too much oil ends up on the electrode of the spark plug, which prohibits the plug from producing the proper spark to ignite the fuel. I would suggest removing the spark plug to see if it is covered in oil. After sitting for a year, it may also need to have the carburetor tuned up or adjusted.

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