Posts
11
Joined
6/5/2021
Location
Morgan Hill, CA
US
Edited Date/Time
6/9/2021 7:04pm
Hey guys,
I’ve been scouring the forums looking for help. However I’m at the point where i am looking at splitting the cases.
rm250 is burning gear oil pretty quickly
- extra smoky exhaust
- the oil I drained is blackened and smells burned
Things I’ve done
- replaced right side crank seal
- leak down tested it and found a leak at countersprocket seal but nothing at the crank seal
- no play in the crank
I’m wondering if the center gasket is shot? That’s the only thing i can think of that is left at this moment. I will if I have to but hoping one of you may have another idea or suggestion
Thanks in advance
I’ve been scouring the forums looking for help. However I’m at the point where i am looking at splitting the cases.
rm250 is burning gear oil pretty quickly
- extra smoky exhaust
- the oil I drained is blackened and smells burned
Things I’ve done
- replaced right side crank seal
- leak down tested it and found a leak at countersprocket seal but nothing at the crank seal
- no play in the crank
I’m wondering if the center gasket is shot? That’s the only thing i can think of that is left at this moment. I will if I have to but hoping one of you may have another idea or suggestion
Thanks in advance
Whats condition of clutch?
The Shop
Time to rebuild
Most bikes have this seal oriented where the metal portion of the crank seal faces outward. The later RM250s were the opposite. The crank side seal should have the metal side facing in and the black rubber "U" portion facing out.
Another thing to consider, how deep was the crank seal pressed in? If it is pressed in too far, it will make contact with the crank bearing which can cause it to drag, overheat, distort and allow oil to be sucked in. Also depending what size socket you used to press it in, the new seal could be torn or warped.
FYI I've been in the process of restoring a 2007 RM250 and had a hell of a time with this issue. Turns out the clutch side seal was in backwards and really made jetting a pain.
I've also screwed up enough crank seal installs that I always keep a few spares in the tool box.
Also another thing to consider, if it has aftermarket crankshaft bearings, the inner ID might be too big.
When I split the cases on my bike it had a Hot Rods crank and Hot Rods crankshaft bearings. During disassembly the crank bearings would literally fall off the crankshaft. The new OE Suzuki crankshaft and OE Suzuki bearings had a much tighter fit. Loose ID crankshaft bearings and improperly installed or torn crank seals can't be good for this.
Just a few ideas of things to check.
The guy I bought it from, it was his dads that used to race back in the day. I’m pretty sure it sat for years which makes me think the center gasket is bad and allowing gear oil to seep into the cylinder. I can’t think of anything else at this point.
I’m going to take the motor out today. Ordered oem bearings last night. Will have to see what crank I have and then go from there.
Split the cases and might have come across my worst nightmare. this part is where one of the transmission bearings sits.
I’m pretty sure I’ll be needing a new crankcase half if I can even find one. Any clue how it could get like this? Man oh man
How many hrs on cases?
Was bearing welded to shaft?
I did notice a brass dowel pin that fell onto the table which I believe is for the pushrod alignment through the case but didnt see this dowel anywhere in the parts manual. This portion goes into the damaged hole. I don’t want to assume but it looks like it goes here.
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