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Bottom End Crank Bearings Blown?

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Okay to start out my bike is a 97 RM 125. I bought it last Feb with a blown top end for 300 bucks. O yeah it’s my first bike as well but not bad I thought any ways I put a new sleeve ($90.00) and piston ($90.00) in the top end. I did 95 % of this bike by myself over the winter. But April can I did a proper break in on the top end. 40 mins after that I blew the bottom end while I was in 3rd gear. Tore the bike apart again for the second time and put a new bottom end in and bearings and gaskets. When the bike blew it striped out 2 gears and both shift forks. So I replaced that as well. About 3 months ago I was riding at about 5000ft and my drain bolt fell out and I rode for about 2 hours before I go back to the truck and noticed. OH S**T I thought fixed the drain bolt problem but now I am worried I might have to go back in to double check and make sure. Because it bogs on the low rpm and smokes pretty good until I get on the pipe then it’s a normal 2 stroke. I get a lot of oil spray out my silencer. Any ideas? Please help :lol::ride:

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Sounds like crank seals. Your clutch and tranny bearings are probably shot if you rode that long with no oil. I would tear it down to check its condition, most likely buying a used engine might be the cheapest fix. The extra heat probably caused all kinds of problems, especially if you were shifting.

Definitely not a throw some oil back in it and go situation. Luckily you don't have a 4 stroke. Then you wouldn't have made back to the truck.

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Sorry to say, but sounds like it's time for a rebuild/replace. Rebuild may be cheaper because then you know what you have. If you buy a motor, it may need to be rebuilt also on top of the purchase price. (Unless too much of your motor is shot.)

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ive got a bunch of 90 rm 125 motor parts and fresh bearings not sure if that will help you out.

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sounds like a bad crank seal.... don't really know. I would replace the rightside seal just to be safe, fill it with oil, jet it and ride!

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I. Put oil in it and rode it around the block it runs but any way to tell if the cases are bad ? What if I just replace my bearings and the seals and gasket ?

Edited by ShortyRm125

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yeah go ahead and do that. be sure to do the waterpump while you are in there. I thinkit has the internal pump.

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