Sparks and burning from exhaust, no control over speed
[ITS A PIAGGIO NRG AIR COOLED 50cc 56 plate.] after riding around for around 30 minutes i noticed quite a lot of black smoke pouring from the exhaust. after having a quick look at it it seemed fine and i thought it could be just oil burning. i did about another 20 miles and i noticed sparks were flying from my exhaust. after quickly pulling over and turning off the ignition i noticed inside my exhaust looked like burning embers off a fire, and smoke was pouring out of it. it took around 45 minutes for the glow inside the exhaust to disappear before i could ride it home. once i pulled off the bike could not slow down and i had to turn of my ignition to stop in traffic, islands etc. what could be the problem and how could it be fixed? the bike is stil restricted and i have owned the bike from new and has been looked after very well. would the problem be covered by the warranty?
Motorcycles - Yumbo - Dakar 200 - 2004 Yumbo Dakar 200
Answers & Comments
You have a unique problem caused by excessive oil and carbon build up. The sparks are from excessive oil burning, as is the smoke, and not being able to shut the engine down or contol it is called pre-ignition. There is so much carbon built up inside the combustion chamber it is acting like a glow plug when it gets red hot.
Beyond that I can't say how or why you are getting the excessive carbon build up, other than from the oil.
Double check the oil level. Maybe somehow the engine is being over filled?
Bill