Don't ignore the glitter in your oil

[sportsgirl0017]

Not to say there was an excessive amount, but there was a bit.

Also though it was hard to tell over the normal 2T noise of an RM250, I thought I was also hearing a strange knocking.

The only undeniable symptom proved to be the rings collapsing. Upon pulling the top end for a believed ring failure found pitting in the head and the piston.

Glad we decided to split the cases...

Luckily no damage to any of the components. Cylinder, crank, cases and transmission are still in great shape. The head needs some smoothing out and some new mains pressed in, but that is it.

It's an 2001 RM and the engine still looked pressed from the factory.

Since getting new jobs and moving haven't ridden it as often as we used to and I would attribute not believing I heard the noise to infrequent rides.

Lesson learned is to just suck it up and split the cases one weekend if you notice any glitter.

Boyfriend is afraid using 10w40 in the last oil change might have had something to do with it too.

[Wild Alaskan]

You found glitter in your transmission oil of your two stroke and that made you check your crank which turned out to be bad? I guess a broken clock is still right twice a day.

[Sierra_rider]

Not to say there was an excessive amount, but there was a bit.

Also though it was hard to tell over the normal 2T noise of an RM250, I thought I was also hearing a strange knocking.

The only undeniable symptom proved to be the rings collapsing. Upon pulling the top end for a believed ring failure found pitting in the head and the piston.

Glad we decided to split the cases...

📎ImageUploadedByThumper Talk1425319951.631773.jpg

Luckily no damage to any of the components. Cylinder, crank, cases and transmission are still in great shape. The head needs some smoothing out and some new mains pressed in, but that is it.

It's an 2001 RM and the engine still looked pressed from the factory.

Since getting new jobs and moving haven't ridden it as often as we used to and I would attribute not believing I heard the noise to infrequent rides.

Lesson learned is to just suck it up and split the cases one weekend if you notice any glitter.

Boyfriend is afraid using 10w40 in the last oil change might have had something to do with it too.

 

If it's "glittery" it's more than likely from normal clutch wear, nothing to worry about. On a 2t, the gear oil has absolutely nothing to do with the crank and piston as you mix does the lubrication. My personal choice for 2t gear oil if ATF, it's cheap and actually has better clutch feel than motorcycle specific oils.

[sportsgirl0017]

Really ATF huh? That's something I haven't heard before but makes sense. Have heard of rotella mixes.

I guess I should have stated that I understand there's always to be a a little bit of glitter, but there's a limit after all.

[rmxdan]

Make sure your replacment main bearings are the correct specification. The cheapest will not be best...

Proper spec should inculde a heat-treated inner race, toughened cage and C3 clearance.

 

There's a bit of discussion on the bearings in this thread.

 

https://www.thumpertalk.com/topic/1054092-eng-and-gear-help-on-a-96-yz250-now-engine-build-opinions/page-2

Edited March 3, 2015 by rmxdan

[Excitable]

how often do you change the oil in the tranny?

[sportsgirl0017]

This may be a poor tactic but when shifting feels 'not as smooth' or if I start missing gears.