1982 YZ490 wont start

[Wreckingball]

m hew to the site. Now i had a few YZ125 and a YZ250 in the past. I found a 1982 YZ490 that i got started once on Friday and have been unable to get it going again? The air,spark,gas 40:1 and compression are good. She pops and smokes but wont start. any and alll help wanted
Thanks
Wreckingball

 

[brett campbell]

Put a new spark plug in for starters. If it still fails to start, pour a little gas into the spark plug hole and see if it starts. If it does then its most likely the carb. If it doesn't then you need to check out the elec. system. That is assuming that it has good compression.

 

[Wreckingball]

the compressions is solid new plug . going to take the carb off today

 

[ellandoh]

sound like timing to me??

 

[RonD]

Yep that's what I was thinking; check the timing.

I had an old '73 CR400 Husky back in the day, and it did the same thing. Turned out to be the flywheel key - sheared; the flywheel was loose!

 

[dirt bike dave]

Bad reeds can make a bike nearly impossible to cold start.

When you have the carb off, pull the reed block and inspect for any warping, chips or cracks.

 

[Wreckingball]

reeds are good ordered a rebuild kit for my carb now just waiting

 

[bultaco4ever]

Did you ever solve this problem? I have an '82 YZ 250 and that bitch is hard to start to...with the kick lever. It bump starts OK. My buddy has a '79 YZ 400 and it has develped a dead spark issue. Nothing seems to be helping his problem. He has an expert working on it that is a bit stumped also. He's going to try a new flywheel. He says magnets can de-magnetize. Ever hear that one?

 

[Wreckingball]

i narrowed it down to source coil 1 and just waiting for it to show up