help me figure out this oil leak, crankshaft seal or shifter assembly?

[regder]

Doing an oil change on the bike and discovered an oil leak, of course the day before I intend to head out on a 3k km road trip.

Noticed some oil residue running down towards the drain plug, so went up from there. Oil filter is dry, oil residue around the front sprocket cover, pulled the cover off and oil residue around the front sprocket. Continued moving up and noticed the shifter cover is right above the sprocket cover. Removed the shifter cover but there's no further oil seal. All the bolts except for one were tight around the shifter cover. The oil residue seems heaviest right underneath the shifter cover so I'm leaning towards that. Figure some RTV sealant should fix that up if it's the problem

Anyone seen something like this before, any more ideas?

 

[RJ2112]

I'm going to go with that's the normal goop that builds up from the 'fling' off of your chain.... except mine ALWAYS looked much, much worse. Your chain looks really dry. What are you using for lubrication, and how often are you applying it?

Second question, it looks like your front sprocket is welded onto the tranny output shaft?

 

[regder]

Definitely not chain lube as I've been using the same dupont teflon lube for a few years now. Chain is a little dry, but it always looks like that with the Dupont lube. I think I'm going to clean the area as best as possible, put some rtv around the shifter assembly cover, and just keep a close eye on it from there.

Strange that it would leak from there though as there is no gasket or seal from the factory and it has never been off.

Front sprocket is definitely not welded as I replaced it myself

 

[FinalImpact]

It almost looks like the FIPG failed. Oh that's Form In Place Gasket. Like you said, they didn't use much so there is little trace of a gasket. One loose bolt could allow an FIPG seal to leak as yours did here.

Clean the mating haves with lacquer thinner and a rag, apply "brand name" FIPG. Toyota makes some good stuff if you have a dealer around. Just apply a thin bead so excess is not inside and getting sucked into the oil screen pickup. Silicone can plug small passages and cause failures from simple repairs such as this. You can apply a bead in a small area, fit them together and pull them apart. Use this to determine the proper amount. You dont need a blob!

As you said, Clean it up and ride it. Its not like its pumping oil out making puddles is it?

 

[regder]

Forgot to update this thread. Had some time to play around with it this weekend. Turns out there is a metal gasket that sits between the shifter cover and the block, mine had bonded itself to the cover and I failed to notice. I ended up cleaning the gasket and reassembling everything, torqueing the bolts to spec.

I put on about 1k km since then, haven't noticed oil dripping anywhere, will take the sprocket cover off one of these days to further check for the leak.

 

[TownsendsFJR1300]

If that stopped the leaking great! That loose bolt didn't help any..

Per the Yamaha shop manual, it gets a new gasket if its removed. It does not mention any type of gasket sealer.

Yamaha makes a center case sealer (for the center cases that don't take a gasket), I believe its called Yamabond, very thin stuff. It would work good on a new gasket if needed.

BTW, if your chain lube doesn't fling any, that part has been leaking for awhile looking at the oily crud in the backround on the rear of the engine/swingarm.