don't trust old spark plugs, lunched my top end

[seanmx57]

I'll get some pics up tomorrow. I ran the plug that came with my slightly used 00 CR250. The plug tab broke off when I was motoing yesterday. Made and interesting and expensive noise. Called it a day. Amazingly it didn't hurt the bore just toasted the head and piston.

Bike wouldn't start so I pulled the plug. Complression was still good. I'll never run a plug from an unknown source again. That engine WAS so close to new maybe 15 or 20 hours max. At least it was the back up/get in shape bike.

[DesertCR]

Looks like you got lucky. BTW I have the same engine in my 03 cr250 and was wondering what jetting you run, I seem to be running a little rich (spooge) but my pilot is stock and I've read that most believe you should go up on the pilot. A little confusing.

[seanmx57]

well I don't know if I'd call it lucky. I check the cylinder walls yesterday, I didn't think the nikasil was messed up, I was wrong, light scratches.

I bet I could have gotten 5 hard years outta that motor easily with just ring and piston changes yearly. oh well. It needs to be ported anyway.

The jetting I'm running would not be interchangeable with an 03, I have a 38 pwk and my reed block is on the jug not the case.

Call FMF they can give you a jetting spec over the phone.