shaft bearings on 1982 550 LTD

[apbling]

I am still waiting for my buddy to put my 550 back together (earlier this summer I burnt a hole in the piston) and was thinking...

When I pulled the oil pan off, the aluminum from the piston was in the sump. It was uniform pieces that you could tell melted, not broke from contact. I cleaned the living heck out of the motor and hosed everything down inside first with WD 40 then I squirted some motor oil around in there. Its been all sealed up since.

What I am wondering is what are the odds that I'll spin a bearing or some sort of other catostrophic event because of the aluminum from the piston? Are the bearings sealed? The motor oil and filter were relatively new and installed properly, so I am hoping that between the pump screen and oil filter the crap would have been filtered out, but I am still kind of worried...
thoughts?

Thanks,
Andy

[kawpaul]

The 550 uses shell type bearings so you should have replaced them and the rings when you replaced the piston. Also do you know why the piston melted? Because if you do not chances are you have not fixed the problem and may burn another one.

[apbling]

I did replace the rings and got by with honing the cylinder. Long story short, when I got my bike out of storage it was harding starting than normal and had a hanging idle once warmed up. I rode it 25 miles on county roads going from 0-65 several times. We stopped for lunch, and took the 4-lane highway back. At about 20 miles into the return trip I started to lose power and then started to smoke. It melted the piston Upon inspection, the only culprit was a torn/cracked intake boot on the #2 carb (it was the #2 cyl that burnt). I must have been running lean and the non-stop 70 mph clip must have just got hot enough to melt it.

Replacing these bearings most likely includes splitting the case, correct?

[kawpaul]

Yes but if you already have the engine out of the frame it is not so bad. But if you feel like you have cleaned it well enough maybe you can forego the bottom end rebuild. Did you flush out all oil passages real well to make sure there was no metal hidden?

The air leak can cause a lean condition which will do that type damage. So sounds like you have taken care of the cause.

[StarGate]

Since the metal was melted and not filings or worn off it should have been in large enough pieces that it would have gone to the pan and remained there. IMO

[apbling]

Thanks for the replies guys. When I had the motor out and the pan off, I didn't see any dirt, aluminum, nothing by/near the crank...all the crap was in the pan, but I still cleaned it for the better part of the afternoon. I am not sure how/where these oil passages are though. I cleaned the ones in the head/cylinders, but how do I do the other ones? Wouldn't they be clean anyway because the screen and filter would have stopped pieces from the pan?


Also, lets say I get everything put back together and it runs. If I would have a bearing failure, would I know it before it was a catastrophe? Maybe I would notice heavy vibration or I could hear it starting to growl?

[zoro]

Have you pulled the head yet?

[apbling]

Yep, I pulled the head and cylinders in May or so. Over the summer I had the cylinder honed, bought a new stock piston, had the valve seats cleaned up. Its all sitting in pieces right now ready to put back together. Why do you ask?

[kawpaul]

Originally Posted by zoro

Have you pulled the head yet?

It always cracks me up when people posts questions that have been answered previously in another post.