sil gp will not start

[kennystag]

Hi All,
My sil gp was running ok but now it will not start, it is banging out the carb, I checked for a spark, nice blue white colour,any help would be appreciated.
Cheers
Stag

[MickYork]

If the banging out of the carb' is a backfire then woodruff key on the flywheel sheared is my first guess.

[kennystag]

Hi All,
I got her started, but now won’t start again. I have been working on cars,and trucks all my days, but that little engine is driving me mad. My first scooter 40 od years ago was a Ld and I never had any running problems apart a Brocken clutch cable, but it did not stop me using it, that is how I learned to drive a motor vehicle without using a clutch. Big deal. Any help on sorting my starting issue will be appreciated.
Cheers
Kenny

[Scooter Paul]

Could well be a slipped timing issue but I have had this sort of problem with a leaking head gasket.

Paul

[coaster]

If it's back firing through the carb I would suspect that the rings have stuck in there grooves possibly as a result of a soft sieze. What you describe is exactly what I had on two of my engines and both had seized rings. Also saw it happen to a GT200 on the way to a rally a couple of years ago, nipped up but it wouldn't restart although it would occasionally fart back through the carb.

I'm also a bit intrigued by the colour of your plug....blue/white?? should be black round the outside and chocky brown insulator

[kennystag]

Hi It was running ok then it would not start, I took of the carb off and cleared it all out put it back on, I tried to start her. After empting my angina spray she started, then she will not go, back fires out the carb. There is a good spark when holding the plug to the frame. I have been working on cars and trucks all my life, but not done much on 2 strokes, this bike is driving me mad for such a small engine.
Cheers
Stag

[MickYork]

did you check the woodruff key ?

[kennystag]

Hi all,
It is now running fine. When I got the bike I put a new plug in, it ran ok for a while then stopped, I then put the old plug back in and it ran ok then died, after checking it all ovev she just would not go, I found a old plug and stuck it in and bingo first kick she starts all the time now. It just goes to show you that a plug that is getting a good spark when holding it to earth does not always work in the engine.
Cheers
Stag