Dead pit bike

[longtravel1]

I picked up a used 110? SIKK pit bike for my son. It ran ok for the first outing. Then it would not start at all. Checked the spark. no spark. Replaced plug. Has spark. It will pop a few times then die. It puffs white smoke out the exhaust. Sounds like a dirty carb or bad jetting. Cleaned carb but still wont start. Does anyone have a suggestion?

 

[longtravel1]

Hello? Anyone? Re-clean carb, timing off, hotter plug??????

 

[Patman]

What is the quality of the spark? How do you clean a carb? Unless you have made sure air or cleaner comes out of the passages it isn't for sure clean. Have you checked the compression? Valve adjustment? May also want to take a multimeter to the electrical system and make sure each piece is performing within spec. If it's popping the kill switch should be OK but taking it out of the equation never hurts. How fresh is your fuel? Did you check the float adjustment during the carb cleaning?

 

[whenfoxforks-ruled]

White smoke usually means its burning coolant. A sick pitbike may be different? Vintage Bob

 

[brentoncole]

the white smoke is interesting but from my personal experience its definitely the timing with these chinese engines they always have improperly timed motors from the factory and some times even loose flywheels take the left side engine cover off and back the nut off the fly wheel and see if it has eaten up the woodruff key or the keyway if it has order a new key and see if that helps. if it hasn't done that see if there is any play and try advancing or retarding the timing by scooting the flywheel about 1mm forward or backwards and make sure you have the flywheel tightened down all the way before you try and test start it

 

[emolatur]

Is there really a reason to "order a new key"? My local hardware store sells them in a truly absurd assortment of sizes.

Got one there for my KX80 and never had a problem...

 

[brentoncole]

only if the key is ate up

 

[Patman]

Perhaps his local hardware store does not sell them. It's more difficult to find actual hardware stores in this day of the mega store.