Were you able to discover the reason behind the fire so it doesn't happen again? I suspect the only thing hot enough to ignite gas vapor would be the exh pipe at full throttle so the temps are high.

Shaun, can you e-mail me pics and price for the wheels as well? Jbonemotorworks@yahoo.com thnx-

It sounds better than my 20' Rockstar with 40 hours on it lol.

If you can't get one due to the holidays, take the exh pipe off and take it to the local hardware store and find a flat washer that fits inside the exh pipe and bolt it back up. Your PW50 has that same thing in it now unless you removed it already, it ... more »

"A more simple way to explain it, basically when the compression requirements exceed the octane of the fuel you are using, the heat of the compression alone becomes enough to ignite the fuel instead of the spark plug causing ignition." I used to think ... more »

Thanks lol

In layman's terms, it is the un-controlled combustion of gases in the chamber at the wrong "time" in the engine cycle which causes engine damage including head pitting, piston crown deterioration, spark plug melting, etc... If heard, (sometimes it is ... more »

easy replace, make sure you send the new one in with the bushings so whoever welds and repairs can clearance it and make sure it doesn't get hung up when flipping open or closed. Powerseal USA in PA can get that fixed np at all- J

hahah

FWYT- "What is meant by "the YZ250 has (2) compression ratio's"? PV closed, PV open. Mr. Robinson-"I think what Jbone meant with the "2 compression ratio" comment was based on the open and closed power valves. You have a higher ratio with the power valve ... more »

looks a hair lean..the outer edges of the squish band show signs of detonation..the wash looks OK. I would have advised you to do a compression test before you pulled the head to see where your PSI is as well as a squish test to see how much space you ... more »

I have not used Royals, only ever used Pro-X. If you do get the crank rebuilt, have the crank builder hog out a little of the plastic stuffers around the inside edges of the crank halves where the rod slides so more oil makes it's way in there. Regarding ... more »

We have used the fmf slip on at first, the 4.1, then we added on the power bomb header and it made it better as well. If you are looking for weight savings, the Ti system is great and saves a few pounds but gets pricey...I would also research dyno sheets ... more »

Powerseal USA in PA can weld, profile, re-plate it, they can also add a better relief around the exh port and bridge. I sent them some cylinders over the years that I was like NO WAY they can fix but they did. DO NOT use a sleeve in your YZ125...many ... more »

are there any flash codes coming off the EFI light?

Thanks for your insight slipdog. I reviewed your posts, you sure know your stuff. Thanks!

Ok, sweet, thanks so much.

sandman768 I truly hate you lol