Bottom End Crank Bearings Blown?

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:

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.

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.)

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

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!

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

And gaskets?

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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