well this morning i went ride, after 3passes(300ft drag) i was idling back to the line when
the banshee just killed, the plugs looked good. the bike is jetted damm near
perfect(slightly fat) maybe.,... well anyways i pulled the stator cover off and saw that a
stator bolt backed out and stuck to the flywheel, the flywheel spun and with the bolt
attatched it busted my stator. i then pulled a good stator off my other banshee and put
it on this one, it started right up and ran fine, after about 5-6 passes on the bike, it
begins to pop and cut out. bottom and top end...i tried different plug caps and plugs and
nothing helped. checked all my wires and connections but could find nothing. i then
thought it was a lean pop so i changed powerjets(this banshee is on alcohol) to a bigger
size. it made the popping worse(so it seemed) what are the possibilities of the cause? i
think it could be that being the timing plate was removed and put bac on today, it coulda
come loose, or the flywheel popped loose???? maybe the reeds have a crack in them? or
the piston intake bridge???? i would definitely appreciate any help you all can give me.
thanks in advance!

 

dont know if this will help at all.. but while riding my banshee suddnely it "got loud", sounded like the pipe fell off, so I got off checked it out, everyting look ok, got back on it, started it back up... still sounded "loud" so I shut it off.. come to find out the "loud" sound was the sound of the broke rod slamming against the still moving crank, when I shut it off the broken rod/piston slid down into the crank bending around it and siezing it.. http://www.geocities.com/yamahabanshee/left.jpg

like I said probally dont help but thats what happenend when my banshee blew up..

 

no it doesnt help at all being my bike fires up every time and still runs, just like crap...it seems to be firing on both cyl's pretty equally when sitting still revving it. also the banshee sometimes backfires when trying to start it, not when riding it...it never used to backfire before

 

when my blaster motor blew up it did that it ran for about 6hrs like that then I pilled the top end and the ring had busted off in the front

 

This may sound stupid, but make sure your air filter is clean and unrestricted. I had a similar problem and tried everything. It turned out to be a very simple fix. I simply over-oiled the air filters and they were not allowing enough air to get into the carbs.

Try cleaning the filters and not oiling them. If the problem goes away, this was the problem.

Good luck!

 

good idea but that wasnt it, thank anyways...

 

I found today after removing the stator cover, one ofthe timing plate bolts was hanging out of its threads rubbing on the flywheel. also my lighing wire from the stator had the plastic coating removed from it by rubbing on the flywheel also....dan hull, person who built the motor, says he has had troubles running his motors with stock coils and they all use a snowmobile coil which is bigger i size and holds more energy and doesnt get hot from the demand like ths stocker does with his motors. anyone heard of this?

 

yes, the exact same thing happened to my friend 1 week ago... and he checked everything like u did, and the bolt on the flywheel kept coming loose, he would start it, it would run fin for like 30 secs. and then iut would shut ofdf and lososen up again, so he went and bought a puller to take off the fly wheel and stator... and found out that there were some wires that were messed up, he fixed those.,... bought a new key that goes in side there... threw it together, started anfd now it runs great. hope i helped.

01 400EX Yellow