help my sled backfires

[f150swartz]

i have a 1975ish yamaha something (gp i think) 433 or 440.... when its idling it backfires every so often and has no power while driving it around, hardly wants to move at times... my uncle says its points, they didnt look dirty or tarnished so i just touched then lightly with emry cloth... nothing has changed and the plugs are new, any suggestions? thanks in advance.

 

[powervalve01]

old gas? the condensor might be fried and causing shortage of voltage

 

[Team Parent Racing]

I would check timing usually flywheel has rust on it, causing timing to be off.

Myron

 

[f150swartz]

old gas? the condensor might be fried and causing shortage of voltage

Where do i find the condenser?

 

[powervalve01]

its with the points the side that moves to open and close taps agints the point on the condersor it might be called a compasator ill look on the yamaha sight and get a diagram of it if i can

 

[f150swartz]

I would check timing usually flywheel has rust on it, causing timing to be off.

Myron

The flywheel is behind the pull start right? And it has plastic fins on it? How would i go about checking timing/ cleaning the rust off?

 

[f150swartz]

its with the points the side that moves to open and close taps agints the point on the condersor it might be called a compasator ill look on the yamaha sight and get a diagram of it if i can

Awesome thanks... what are the things wrapped im wire beside the points?

 

[powervalve01]

take some fine sand paper and rub lightly on the outer edge of the flywheel and itll clean it up the timing in ont of those is all in the points

 

[powervalve01]

the stator will be attatched to the flywheel i believe

 

[powervalve01]

im not sure what is wrapped in wires if u can put a picture on it or u can email it to me if that will be easier

 

[f150swartz]

take some fine sand paper and rub lightly on the outer edge of the flywheel and itll clean it up the timing in ont of those is all in the points

Would you be able to explain or show me a link on setting points?

 

[powervalve01]

ill look around and search what the gap should be on the points

 

[powervalve01]

the point gap is suposed to be 0.014-0.016 when wide open

 

[f150swartz]

So how do i gp about setting the gap?

 

[powervalve01]

once u get it apart theres a screw losen to adjust if u need to check it when the points are wide open out a feeler guage in between them if theyre black theyre shot

 

[f150swartz]

once u get it apart theres a screw losen to adjust if u need to check it when the points are wide open out a feeler guage in between them if theyre black theyre shot

ok thanks... i havent got to it yet. I will shortly supposed to warm up here its cold in the garage lol