Guys I’m working with a yz 490 and I can’t seem to get the damn thing to run forwards. Starts up but runs in reverse. What ended up happening before all this was the stator came loose jammed the magnito and sheered off woodruff key I replaced necessary Parts and runs backwards. I’m wondering if when the woodruff key sheered it turned the crank balance off any idieas...?
Help 2 stroke running backwards
- Thread starter Mjusza
- Start date
When you see this happening it's usually an ignition phasing issue. Closely inspect all the parts in the system for signs that something moved from it's original position. If you can't find it that way you'll need to verify where the ignition is picking up it's firing signal versus crank angle and piston position. This is more work and requires a few special tools like a piston position/TDC dial indicator setup and a degree wheel.
Usually you can spot the failed part under very close inspection.
Usually you can spot the failed part under very close inspection.
- Thread starter
- #3
So what happen was one day I was riding it and the stator bolts came loose and jammed up my magneto. Obviously it died I thought I blew it up. I dig into it and find that it sheered my woodruff key off the crank shaft. I’ve replaced it with a new key and since have zero luck having the bike to run forwards. I put it in gear and if I’m even lucky enough to start it, it goes backwards. I though that maybe the crank balance went out due to the sheering of the woodruff key and the piston not hitting top dead before firing?? I dunno I’m lost. Also meanwhile trying to kick it over while adjusting the stator to several different degrees I’ve had the kick starter back kick on me and cracked the housing and on a second attempt broke the housing cover. Any help would be really be appreciated thank you for thanking the time.
Rick is there some more info you can give on behalf of checking the timing. I now have the half’s split due to the broke off piece of my case from the kick started not returning due to the spring coming out of the shaft orfice and once it fired it slammed upwards and nearly shredded my shin off. Why would it do this???
Rick is there some more info you can give on behalf of checking the timing. I now have the half’s split due to the broke off piece of my case from the kick started not returning due to the spring coming out of the shaft orfice and once it fired it slammed upwards and nearly shredded my shin off. Why would it do this???
