I put an 11.1 Je piston in my Raptor over a year ago and the other day while riding it quit with no warning smoke or anything of the such. I could crank it around by hand so I knew there was no compression. I tore it apart and found the piston had a pea sized hole all the way through it. It wasn't burned through it just broke and cracked three different directions. it didn't suck a valve and wasn't hit by something sucked into motor so what the hell happend to my piston?

 

thats odd. i'd send it to JE for failure anaylsis. http://www.jepistons.com/

 

scoobydfw,
what kind of EE work do you do? I'm an RF engineer or EE also. I wish that we had some job openings here in Phoenix at Motorola. If I hear of anything, I will let you know though.

ba01raptoraz

 

thanks ba01raptoraz. i do mostly digital design, VHDL, FPGA, ASIC, high speed board design.

 

my je did the same thing except it was from too many lean runs on nos.
my answer is that the jetting is too lean which has been causing slight detonation (even the kind you cant really hear) that over time has taken its toll. also, pump gas is borderline with 11-1 depending on what kind of riding style you have. of course if you had race gas then i would lean toward jetting.

 

I always run sunoco mixed 50/50 with 91 pump. anyways it was not lean, it had been running rich all day long.

 

this is why i would regret jetting, adding a better piston to my rappy, not covered by warranty and tend to not work alot...but u gotta do it for the hp/torque...