i rebuilt the old banshee a month or so back and have only put about two hrs ride time on it .well this weekend i had a piston skirt to break. its missing all the way up to the top of the intake window on the piston, so guess where all this went at wide open throtle.yep it toasted the nice rebuilt motor,cylinder scratched ,head chewed up and lots of little piston goodies now living in the crank case. i would absolutly not recomend these to anyone that has a high performance motor.anyone have a idea of what its going to cost to get the old girl up and going again?

 

i have never heard of namura, and im glad you mentioned this before i tried them out.

 

2 hrs doesnt sound like enough break in time for a rebuilt motor especially at wot.

late

 

kemicalburns,
it had been heat cycled several times along with casual riding,it had only been opened up a handfull of times before the big kaboom! i felt like it was ready to sling some sand, but it decided for a piston instead.

 

For a 2 stroke, 2 hours is plenty of break in time. I have heard of Namura.....just not much from them. I asume this machine was bored....did the guy match the pistons too the bore job? My bro rebuilt his Banshee recently and went with Yamaha OE parts because of such good service on the stock top end. The guy boring his cylinders said the new OE oversize pistons were off by an astonishing .008 and .013! These were sent back and Wiseco pro lites were used and the cylinders were bored too the pistons. Sorry about the misfortune Vision. Magnolia Tractor Supply was the cheapest on his parts BTW.

 

I had the same type of problem with my old banchee and those pistons. I just had the engine rebuilt (crank, porting, cool head ect...) and rode it for a couple of hours. Nice and easy for the break in and then started to get on it. Lased 10 hours at the most and then started to rattle. Pulled the plugs and one had metal all over it. Pulled the cyll and the piston broke. The guy that built my motor sent them ack, got the money back and went with weisco.

After 2nd rebuild checked the compression and had about 200lbs per cyll. Way higher then it should have been, found out the cylls were shaved down. Had to buy new domes to get the right compression. Ran great after that.

 

Ridley, 200lbs of compression is INCREDIBLE!!! I don't think they make gas high enough octane to cover that in a 'shee. 158-165 psi is the breaking point of 93 octane... I detonated w/ 18cc domes and 93octane(bought used didn't know), I now run 20cc domes now and its cherry.


Mike

 

If you are going re-sleeve one of the cylinders might as well do both and go big bore with Vito's kit $600, cost to resleeve jugs and machine $300. If it didn't hurt the upper case.

 

No problem[img]i/expressions/face-icon-small-smile.gif[/img].


Mike