Oil behind the advance mech cover

[jurgenkoppen]

Did anybody ever find a small puddle of oil behind the advance mechanism cover?
I had to install the advance mechanism on my project bike, and decided to adjust the timing a few weeks later.
Had a little oil inside (behind)the cover, and pleeeese tell me it is not coming from where the main crank comes through......
There was not a lot of mess inside there, no dripline coming from the crank, just a little puddle at the bottom. Since then I notice a spot of oil dripping off that side, from the large bolt directly below the advance cover....
Hoping it might leak from there, and wind just syphons it up through the small breather gap into the housing.Wishful thinking?
Any thoughts? Thanks, Jürgen

[79XS11F]

Well..... the crank seal is the only place under that cover where oil could come from unless what your seeing is oil you yourself used during rebuild / assembly of the timing unit.
Now the good news if that's not the case ... Replacing that seal does not demand splitting the cases. New seals press in once the old ones are removed. Replacement seals do not have lips.
Rob

[John]

That's right, just keep trying to convince yourself that the oil is migrating uphill from the oil galley plug and getting in behind the timing cover. Truth be told, the leak is coming from the crankshaft main seal that is behind the governor assembly (mechanical advance). The OEM seal has a raised lip on the back side of it where it sits in the case, but it can be carefully pried out. You can pick up a new seal at any seal and bearing supply house.
The P/N is: 32x48x8. Those are actually the dimensions of the seal, as well as the P/N. The new one can be carefully driven in with a hammer and a piece of wood. Use the wood to contact the seal, and the hammer to contact the wood. The seals are not expensive, so get a few, just in case... Be sure to lube the seal well before installing it.

[jurgenkoppen]

Seal it is

Rob and John.

I figured that I might indulge in wishful thinking, but in a sense your info is not as terrible as I anticipated. I'll find the new seal and be on my way.
Thanks for taking the time to give me the info. Cheers , Jurgen

[thewiz]

crankshaft seal

I had a similar problem a few months back on a bike that hadn't been run in a few years. More than just a drip .... ordered a new seal from the dealer but unfortunately it DID have the lip on it ... so I just deferred doing anything as the bike wasn't ridden much anyhow .... low and behold; after doing some tuning and a few short rides the leak slowed to almost nothin' !! The oil level is normal so I think that I may have overfilled it initially to some extent thus possibly causing the leak to occur ..... there is a pretty good thread on this by Portero. I checked with him recently and he said that the repair had been holding for a few thousand miles and has showed no signs of giving out ...

[John]

Another cause for the seal to leak is XSive pressure in the crankcase. My bagger had a leak on the left side, and I was preparing to do the fix, but before that could happen, I was running it up, and suddenly the case breather hose blew off with a loud pop! It seemed somebody had made a 'sillycone' plug and inserted it in the nipple in the airbox where the breather hose attaches.

[dbeardslee]

Careful if you take that galley plug out. I think they're made out of potmetal. It takes VERY little wrench pressure to snap that little sucker in two. Don't ask me how I know

[jurgenkoppen]

Portero

Thanks for the lead to Portero's thread, that was most helpful. Now I am really on my way, after I make sure my vent passage is all clear......
Another angle:
I do have a little bit of vibration at about 5500-6000rpm, feeling it in the footpegs, (but noticable not in the mirrors) .
The worst possible scenario is a slightly bent crank causing vibration and leaky seal. My theory is: if I do not spell out this paranoia, it will fester in my mind. So tell me it is highly unlikely...? I have heard/read that the xs11 cranks are the toughest cranks around, used often in drag/racing machines...true?

[thewiz]

I might be steppin' over the line here....

BUT, I believe that even a slightly bent crankshaft would exhibit much worse symptoms than just a little vibration. So it's probably safe to relax on the one .... .... Screw a bolt to use for a handle into the crankshaft snout and give it a wiggle in all directions ... see what kinda' play ya' get ... also check to be sure the vent passage way to the airbox is clear and that the oil is in the middle of the marks. It's been 30 yrs since my first 11 .... but I STILL have a hard time reading the oil sight glass. Almost takes two people sometimes ... specially if you're a short guy like myself .... one to watch the glass and another to rock the bike back and forth.

[digitalsam]

Removing the Oil Seal

OK, so I gambled and lost. I thought I could use the old seal and save $20. Now how do I get the old seal out without dropping bits into the case? And what is the penalty if I do drop bits in?

[trbig]

$20?? Shouldn't pay more than 6 or 7 bucks. Don't get one from Yamaha.. they'll have the inside lip and you'll either have to split the cases to put it in or grind that lip off.

Shove/tap a screwdriver through the old seal and pry it out. Shouldn't be any bits.


Tod

[thewiz]

The seal you need is a 32x48x8 ... you can get them in Viton or Nitrile ... I have used both .. the Viton seal was about 20 bucks and rated higher in resistance to heat ... the other is like Tod says ... either is fine. Trick is gettin it in there dead square.

Takes a while on yer belly to dig a factory style seal out, 'specially it's old and dried up. Just be careful not to gouge the shaft or case while digging. Also pay attention to possible wear on the crank snout ... I have not yet seen an XS with a deep enough wear mark on the crank snout to cause leakage but I'm sure it's possible.

[digitalsam]

Rotor pulling tool

The local O'Reilly's had the crank shaft seals for $8 a piece. I ordered them and am ready to install them as this weekend.

So then, I stopped by the local Fastenal to pickup a 16mm 1.5 pitch bolt to pull the rotor off. I never could get it off with the three legged puller tool. They wanted to know how strong the bolt needs to be? I have no idea? Anyone? I thought steel was steel?

Anyone have any other tips for how to get the alternator rotor off of the crank shaft. It seems to be stuck pretty good.

[bikerphil]

The one I have says 10.9 strength rating on it. If you bought a lesser one already, it should still work. Wait till you see how easy it pops off with the correct tool.

[digitalsam]

I found one online 10.9 strength, would 50mm or 2 inches be long enough?