2003 RM 250 - Gouged Cylinder

[1999RM125RIDER]

I just pulled apart my top end and the piston and cylinder are very gouged...two areas maybe a half inch wide and about 50-75 thousands of an inch deep...there's also a little bit of damage at the ports. My questions are:

1) any ideas on what caused this to happen to my bike?...it just died in the start gate...it looks like a ring may have broken.

2) can the cylinder be fixed? nikasil? or i've heard you can bore it out and install a steel sleeve?

3) do i have to split the cases? there are some metal shavings around the top end, can i get these out of the bottom end by flushing with oil or ????

Help!... i don't want to do any more damage to the bike!

 

[1999RM125RIDER]

i read in another thread that installing a steel sleeve is like going back a decade or two in technology compared to doing nikasil...any comments on why this is?

 

[dan druff]

I just pulled apart my top end and the piston and cylinder are very gouged...two areas maybe a half inch wide and about 50-75 thousands of an inch deep...there's also a little bit of damage at the ports. My questions are:

1) any ideas on what caused this to happen to my bike?...it just died in the start gate...it looks like a ring may have broken.

2) can the cylinder be fixed? nikasil? or i've heard you can bore it out and install a steel sleeve?

3) do i have to split the cases? there are some metal shavings around the top end, can i get these out of the bottom end by flushing with oil or ????

Help!... i don't want to do any more damage to the bike!

i can help with the cyinder part. if you can run your fingernai lightly around the cyinder and feel the gouges its time to get it replated. I woud reccomend MIllenium Technologies. Contact them, then send your cylinder and they will replate it for you. you can also order the parts (wiesco) needed to rebuild the top end from them as well. they do a very good job and have a remarkeby quick turnaround time. I wouldn't go any where else. they will also send you detailed instructions how to properly re-install your cylinder. don't get a sleeve, they are bad in more ways than one, plus the sleeve dosn't last as long as nikasil.

as for what may have casued it, if your ring is broken which you say it is, it is a pretty safe bet that did it. it could have been running too lean as well. did it just die, or did it sieze?

 

[1999RM125RIDER]

just died...there was no compression after it died but nothing seized up...upon closer inspection it looks like the lower ring broke...the gouges in the piston and cylinder match the width of the ring and it looks like the piece slipped below the piston and into the crankcase...problem now is how do i get it out of there without splitting the cases...i'm gonna try turning the bike upside down and turning the crank and hope it comes out...but if it doesn't, i'm considering just leaving it in there...there's not much down there other than a spinning crank, how much damage can a small piece of ring do? any thoughts on this??? am i taking a big risk just to avoid extra work??

 

[loudandproud]

i'm gonna try turning the bike upside down and turning the crank and hope it comes out...but if it doesn't, i'm considering just leaving it in there...there's not much down there other than a spinning crank, how much damage can a small piece of ring do? any thoughts on this??? am i taking a big risk just to avoid extra work??

OMG, get that out of you head right now. :bang: :bang:

I first of all it isnt going to come out, plus you are gonna have metal flakes in your bottom end. These will destroy your bottem bearings and ruin the motor again on top. >>>> :yell: <<<<< (you)

If stuff is in there, take the time and do it right, split the cases. :nod: