Please help me with my RM250!

Hi Guys! :smirk:

Ive posted before about this bike but Ill start from the top. I think it may be hard to explain so bare with me and I hope I dont miss anything.

I bought an RM250 as a bit of a project. The fella told me it was a 98 with a 99 engine. After putting some pics up here a few of you good people comfirmed that it was a 98. And after doing a fair bit of research I found out the engine was a 99.

The fella had broken a piston up and there was lots of pieces in the crank area. He didnt say but I assume he just got fed up with the bike and wanted rid of it. He already got a KXF so didnt need it. When i picked it up the cylinder/piston were stripped off the bike. I had the cylinder which looked fine to me.

Anyway when trying to fit the cylinder on the engine it clearly didnt fit! After more research and help again off you guys turns out he gave me a 98 cylinder with the 99 engine! Obviously no chance of it fitting. So I was missing a 99 cylinder and head and obviously the power valve assembley.

So I found a perfect cylinder and head on ebay for 75 quid. He 100% promised me it was for a 99 as he brought the bike it was fitted to in 1999. Its pretty much brand new, and it fits the bike! Then all I needed was the power valve assembley.

I couldnt find one in the UK, but found one in the States which is on its way over. I have a clymer manual now and im even more snookered now.

This is the confusing part...

The 99 and 2000 cylinder are identical in everyway apart from two things. The 99 has a breather pipe with a filter on the left, and the 2000 has a pipe on the top which I believe goes to a solenoid. So it turns out I have a 2000 model cylinder! This is now a problem as I dont have the powervalve solenoid as my loom is a 99 to go with my 99 engine. Here I think are my options....

Buy a solenoid (but how would I then fit it to my loom?)

Buy a solenoid and a whole new loom (expensive)

Buy a solenoid and get the soldering iron out (dont fancy this)

Change the pipe that would normally go to the solenoid for a much longer pipe and use it as a breather (the 99 cylinder does this only the pipe fitting is on the side not the top?)

Block off the pipe that goes to the solenoid

Any ideas? Sorry for such a long post. Bit baffled with this one. Thanks!

Jeez Louise, it sounds like you are building a Frankenbike! :smirk: I admire your abilities. Regarding the PV Solenoid, there is an active thread on this issue here:

In short, if you want it to simply run, either leave it unplugged and run it or plug off the opening. Maybe try both and see which one you like best (wrt pinging and power delivery). I would stay away from finding a different wire harness and solenoid and.. and... and... Seems like a neverending goose chase.

Good luck, and more importantly, GOOD JOB!

Thanks for your kind words. I would never of purchased this thing if I were to know it was a mix n match bike.

It's just the 99 cylinder runs with a breather pipe with a filter inside and runs fine. But the 2000 needs the solenoid? And both are set up the same. Bit strange

I suppose I could block off the pipe that would go to the solenoid, and drill a hole and secure a fixing where it is fitted on the 99 cylinder. That way making it identical to the 99 cylinder.

I'm a new ish mx rider. Haven't riden for years and when I did it was brief. I'm not new to bikes or spannering (although I'm no 'expert') so I don't care if the bike doesn't run 100%, because I'm crap anyway. But I don't want it to blow it's self up! I need a reliable bike

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now