Oil leaks need ideas

[Rlauchard]

Morning....while I'm sitting delayed at the airport I figured I'd think about the bike.

I have had my engine out of the frame for a few months now sitting on the workbench. It continues to seep oil out of a few places. Mostly it looks to be coming from the oil pan bolts.

I'm using a silver crush washer that I got from a Yamaha dealer that said they were similar to copper. I'm not sure if this is the issue or not. Can you guys offer up anything on how the bolts are properly sealed?

I spent a lot if time cleaning and rebuilding the engine...hoping I can prevent some if this.

 

[Paulrxs650]

I would say that the gasket has gone too. Whip it off, clean the surfaces carefully, new gasket and for belt and braces some gasket sealant too.

 

[Rlauchard]

I replaced all gaskets already...the oil is coming down the two front bolts studs on the bottom and the acorn heads....

 

[gggGary]

Yes it's all about the gasket and cover. Those bolts didn't have washers from the factory, IE not needed.

97011-06025-00 BOLT (97001-06025-00) $0.68 6 PART OBSOLETE
They were not a standard bolt.

In somewhat random order;

Is the gasket surface clean AND flat on both sides? After carefully razor blading all gasket remnants off both sides I like to CAREFULLY work a file across the cover looking for high spots, around each bolt hole is common and a ridge where someone has beat the front trying to get it off because a PO used gasket cement on the cover. All thats needed is a light smear of oil or grease on both sides of the gasket. Others have suggested a 1/2 drill bit BY HAND lightly making a SMALL bevel around each bolt hole this will help the cover clear if the case bottom has threads lightly raised from previous tightenings.

The factory bolts were weak by design to keep junior armstrong from stripping the threads out of the bottom case. You know the the kid sweeping the shop who wants to help Yeah sure, change the oil on that 650 over there....... Crrannkk, Snap! Crankcase saved. Kid gets a lesson on skill vs enthusiasm. LOL

With a new gasket and smooth gentle bolt tightening no sealer or bolt washers are needed. it's a big flat surface easy to seal. oil is sneaky the source may be somewhere else. Clean with solvent and watch for a day or two. Puff a bit of talc or foot powder it will show up oil trails revealing the source.

 

[5twins]

I think he's talking about the two chrome acorns on the lower front of the case. Mine sweat oil too. They don't actually leak or drip, just sweat. They are supposed to be sealed with copper washers. I pulled mine and annealed them but they still sweat. Maybe I need new ones.

 

[retiredgentleman]

Yes, there are 5 or 6 small chrome acorns on the bottom of the engine. As I remember, 3 or 4 of mine would have a drop of oil showing at times. I took each one off, cleaned them well, coated the copper washer with some Threebond1104 sealant, and re-installed. No more oil leakage after doing that.

 

[5twins]

Hmmmm, I'll try that next. Thanks for the tip RG.