Missing Crankcase Piece

[rustysparksalot]

I pulled the jugs off my 1980 GS550L this morning, and I was carefully removing the gasket when I found this piece on the rear left side of the crankcase missing. A small oval-ish o-ring sits in the recess.

The right side has the same recess, but the tiny lip that would touch the piston is not broken off. You can see more pics of the broken one, and the intact side if you follow the link.

http://s1276.photobucket.com/user/rustysparksalot/library/

I'm wondering if any one has seen this before, and how bad it might be. I don't think this piece came off with the gasket. The valves on this cylinder and the others were too tight. Would this missing piece of crankcase lead to a lot of blowby? The cylinder and piston look ok, but I did have some smoke coming from my breather hose at the top (pods no airbox from PO).

[BassCliff]

Hi,

Hmmm. I've got the jugs off of my 850 right now. I'll have a look when I get home tonight. Does it look like yours is chipped?

Here's mine, but I'll take a couple of closer pictures this evening.




Thank you for your indulgence,

BassCliff

[rustysparksalot]

Yours looks good to me. It even looks like it's got more meat than my good one.

My chip is on the circumference of the hole for the piston, opposite the starter in your picture.

Mine definitely looks chipped, like it's not supposed to be missing.

Looking at your picture, maybe blowby wouldn't be so much of a problem, because the crankcase isn't sealing tightly against the piston and rings.

[BassCliff]

Hi,

My chip is on the circumference of the hole for the piston, opposite the starter in your picture.

Mine definitely looks chipped, like it's not supposed to be missing.

Perhaps a previous owner got too physical during an old gasket removal?

That is an oil channel. I would be concerned that the path would leak back down into the crankcase instead of making it all the way up to the top of the engine to oil the cams. It looks like it could loose some pressure along that path. I'm no expert at the engine oiling but perhaps other might want to express an opinion. I don't know if that can/should be repaired. I suppose the O-ring and gasket would be mostly sealing that area.



Thank you for your indulgence,

BassCliff

[Agemax]

i would say it will be fine to use. the block will compress down the gasket and the egg shaped o ring and seal off that little part that is missing. therefore getting full oil flow up the passage way to the head.

[rustysparksalot]

I just wanted to follow up in case any one has a similar problem and finds this thread.

I've reassembled my bike, and I don't think this minor blemish has posed any serious inconveniences.

There's someone else, who did or is doing a much more skilled rebuild of their 550, and I could see in one of his pictures, that he had this same "problem." One heckler on that thread called attention to it, but no one seemed to think it was a big deal there either.

Many, many thanks to BassCliff and Agemax and everyone else on the forum for their help.