I'm not sure but the 105mm might be a different casting and may not have the same problem. I hope that's the case.

 

Hey, Sixsixty, I think you may be right, I run both bikes 105.5 je pistons and I put one to the test this weekend with too much sause and not fat enough on the jetting and it still held up, and the other one was on alky and has ran lean before and held up. So it must be different casting.

Dave, your bike took a dump? That sucks, I hope JE hooks you up. I think you may just need to get a big cylinder and try a 105. Come on now. Your bike is telling you something.

 

My wiesco 11:1 has heald up through 15 months of abuse, and running lean once at dumont. I havn't got any complaints about it. It is only a 100.5mm piston tho

 

CP is the best piston i have ever run. I have about 65 hours on it know and it is still stroken. I heard JE isnt very reliable. Try CP for once i think u will like it. I am running the 12:5:1 in my DS and Love every min. i ride it. [img]i/expressions/face-icon-small-smile.gif[/img] Lance

 

I think the problem is only with the 11:1 JE, maybe the extra meat on the 12:1 is in the right spot? Or have there been problems with the JE 12:1 too? My new Craycraft 730 has a Ross.

 

Yeah, is it only the 11:1 that is having problems?

 

Not to change topics, but what are you guys that are running the 12:1 pistons getting for compression? Also what size of pistons are you running? I just want to make sure I am the same or close to the same as everyone else.

Also as far as the 12:1 not having problems, I know when I ordered my piston (back in December) I had to wait a few weeks because there weren't any pistons availabe, and JE wasn't producing any because they were redesigning the piston. Or at least that is what they said was taking so long.

Thanks

 

Do they have a website? Do they sell pistons for Raptors? TIA

Yes Mario. Saturday about 2pm. Racing Larry and a YFZ up the hill just before we shut down, the bike decided to shut down itself. Coasted to the bottom and watched for another hour or so before I did the ride of shame behind Larrys DS. LOL. I'll be back though. Sam has made me a good offer and the 12:1's haven't seemed to have this problem. I'll check around to see what I can find in the way of Raptor pistons before going with Sams offer. Just got the crank today to put the blue Rappy back together so I'll be busy with that for awhile.

 

Wiseco does make an 11:1 102mm Raptor piston. They just started selling them.

Yamaha Parts List (PDF)

 

Great suggestion!!

DAVE- I just happen to have a raptor sleeve 102-103mm. I will GIVE it to you for free, then alls you would need is a higher comp piston. Done deal!!!! Ill give it to ya just cause your my homebizzle.