4 stroke problems...

[Yamatrike400]

As you may know already i have a yamaha 400 motorcycle with a atc rear axle and wheels. The last thread i posted was leaky carbs and that is now fixed i put in new gaskets,needle,seat. Well,she wont start,the only reaction i get from it is some flames shootin out the exhaust once in a while(tried with exhaust on,and off). Maybe a 4 stroke guy could tell me what could possibly be wrong? i did not touch the valves at all it ran fine before i tore her down for the tranny rebuild. any input would be great.

[KLT110]

i think tht *Edited**Edited* valves may be outa line
usually when fourstroke spit flames i heard theyre blown

[300rman]

well, if it ran fine before the tranny rebuild, i would say something isnt put together properly. could be the valve timing, other than that, i cant say without playing with it myself.

[money89tractors]

When you rebuilt the engine, did you get the timing set right? Many people mess up by puttin the cam in wrong, which makes the timing 180 degrees off...

-Phil

[Yamatrike400]

All i did was put in new gears,i did not touch the cam, timing chain ,nuthin.And there is only 1 way to mount the stator so it must be right??It sparks fine and is getting gas.I did notice some oil getting on the spark plugs though???

[300rman]

yeah, if the stator is in the wrong place, it will fire the fuel at the wrong time.

[Erics350x]

remove the flywheel and check the flywheel key for damage

[Yamatrike400]

No flywheel key,it mounts on a splined shaft.And if it was broken,it wouldn't turn over.