Need Input ASAP 1990 RM250 $200
- Thread starter JakeBoucher
- Start date
Yeah throttle was wide open, plug looked like new. I think someone was messing with it at one point.
Pulled the topend. The cylinder was worse than my other rm250. The piston was a single ring too?? I'll post some pictures later tonight.
Looks like the cylinder has done it's job....you could put 400$+into the top end and hope after you get it running with no other major problems, you could probably still make money on it. But it's a gamble nothing else will cost ya...you can get pistons with 1 or 2 rings, depending on what you want, some people say 1 is better because it revs quicker,wears on the cylinder less ( less friction) others say they like 2 rings because it provides more compression, and it doesn't matter on durability since 2t top ends are changed out so frequently....I've used both and don't believe I have a preference.
I'm going to part it out or sell it as a repair bike. Thanks for the clarification on the piston rings. With only being able to get 3 rebuilds out of a replate, 1 ring doesn't sound so bad lol.
3 rebuilds at most, there's the school of thought that while 2 rings give off more friction, it also stabilizes the piston In the bore more than the 1 ring setup does, thus causing more even wear and helping prevent the egg shape or outa round cylinder. But like I said before, that's just what others say, I'm not that concerned.
Wow that really sucks it costs $225 to get a cylinder replated and you get 3 rebuilds at most. I can see how the 2 rings do that, sounds like they both have pros and cons.
Wow.....don't think I've ever gotten past the 4 th tear down without replating....which pretty much is in line with what my riding buddies tell me bout they're own experience. I've had couple of guys from different local machine shops tell me the same. Hell maybe that silkolene you use does do miracles.
On rebuilds you have to figure apples to apples. I think the hours the cylinder runs mean more than piston count. I run 20-1 mixes, get 4-6 top end changes on a 139 or 144 yz 125. 30ish hours on a piston. Same mix I couldnt change out twice on the cr500 over the years and get a new feeling from it. on the cr250 the current cylinder is 3 at nearly 50 hours pn each. Looks like it will go 3 more on a guess. (first cylinder got lots of water in it on the second piston and the cylinder and crankshaft got changed out). So it kind of comes down to how it is ridden and oiled to me and how long the rebuilds go. FYI I use dual rings about half the time on the yz139 as they hold compression a noticeable amount longer.
In the past the suzukis and kawasakis I have owned or been around didn't have plating that held up was well as what the other makes offered. the 1990 was a boron treated one similar to my 87 and 88 suzukis were. Those wore as fast as an iron liner did.
You have to really like a 25 year old bike to put a thousand dollars into it.
In the past the suzukis and kawasakis I have owned or been around didn't have plating that held up was well as what the other makes offered. the 1990 was a boron treated one similar to my 87 and 88 suzukis were. Those wore as fast as an iron liner did.
You have to really like a 25 year old bike to put a thousand dollars into it.
Maybe, no idea. I do have a 91 kx80 with the original topend and clutch in it and an estimated 1800 hrs...it's only ever seen silkolene.... Tho that can happen with any quality oil I presume. I think my kx250 has 5 rebuilds on the top end.... Maybe I'll tear it down this time and need a replate...who knows