Sump o-rings

[raychappo]

I'm going to replace both o-rings on the sump where it pushes into the transmission case while I have the engine stripped down. They both look identical but in the parts list there are 2 different part numbers. Are the the same and that there are 2 different numbers for the same part?
Ray

[timpa136]

Ray, my guess is size and I would guess the larger one slides back on second. I was thinking they had a third o ring to act as a dust or overkill sealing but I don't see it pictured either. Do you have it apart now? Bottom line, I don't know either. If you have trouble matching them up, I will check over here.
Timpa136

[raychappo]

The sump is off and both rings measure the same. I'd have thought if the o-rings were different the would each have a different item number in the parts list but both are listed as item 19 in the parts list.
Although looking at the list it quotes 2off 09280-44004 and 1off 09280-52003. Perhaps some bikes have a single ring and others 2?

[timpa136]

Although looking at the list it quotes 2off 09280-44004 and 1off 09280-52003. Perhaps some bikes have a single ring and others 2?

You are right. I think the early ones had a third larger o-ring next to the fins. pt.# 44 Q (2) and 52 Q(1) might mean diameter
and they found it wasn't necessary in later bikes, still don't know.

[nairb]

Very useful thread. I have the engine in bits and was going through the seals needed on the oil sump... 2 are the same with 1 larger. Fortunately fleebay came to the rescue with some similar sized ones.