Leaky Casing Concern

[Adamc]

Hello one and all.
I’m new here, and new to the XS650 (60/70’s Honda man before!)
Just acquired a 1979 XS650 modded bike I’ve been chasing for 20 years!
Has been in some guys man cave as a show piece, not used for far too long.
After checking through usual stuff (fresh fuel/new oil/filters/plugs etc) it started first time.
Runs ok but idles poorly, carb issue I will check out.
Overnight an oily petrol smelling leak dripped out of the left hand casing cover.
May have left petcock on reserve.
Could this be from cylinder flooding and dry crank seals?
Any advise would be helpful before I continue this project.
Bike pics will follow.
Cheers
A.

 

[Jim]

Welcome to the forum!
Could be the crank seal. More likely would be the clutch pushrod seal or the tranny output shaft.

 

[jetmechmarty]

Yeah. If it has been sitting dry, you may have several seals to replace. A nice bike stored in the house is going to need nose to tail service. I believe I would replace engine case seals as they show themselves as leakers. Lucky you! There aren't very many. Clutch pushrod seal is #1 as Jim pointed out.

 

[maico996]

Guide to Buying - Get to Know your bike, a checklist for the condition of your find | Yamaha XS650 Forum

 

[Mailman]

From Gary’s secret files of usual suspects.

 

[Adamc]

Welcome to the forum!
Could be the crank seal. More likely would be the clutch pushrod seal or the tranny output shaft.

Thanks for the welcome; and responses already from far afield.
This is reassuring that you guys are willing to help an new XS650 owner.
Cheers all.

 

[Adamc]

Yeah. If it has been sitting dry, you may have several seals to replace. A nice bike stored in the house is going to need nose to tail service. I believe I would replace engine case seals as they show themselves as leakers. Lucky you! There aren't very many. Clutch pushrod seal is #1 as Jim pointed out.

Thanks Jet, all info greatly received; I think its the crank seal looking at where the leak is after removing the cover.

 

[Adamc]

Guide to Buying - Get to Know your bike, a checklist for the condition of your find | Yamaha XS650 Forum

Thanks for the link Maico996, All is helpful.

 

[Adamc]

From Gary’s secret files of usual suspects.
View attachment 195268

Cheers Mailman. Great image. Its the crank case seal looking at your pic.Following a full service & fresh fluids would this seal close up or am I looking at a rebuild just for the seals? Can the seals be replaced without splitting the cases?
A.

 

[Mailman]

Here’s a couple write ups I did, there’s lots of others here on the forum. Use the search feature on the forum and search seal replacement. Some other guys have some slightly different techniques on the clutch pushrod seal. They can all be replaced without tearing down the motor. Best of luck to you!

http://www.xs650.com/threads/engine...shaft-seal-driveshaft-seal.52591/#post-556675

http://www.xs650.com/threads/replacing-engine-seals-part-one-the-shifter-seal.52589/

http://www.xs650.com/threads/replacing-engine-seals-part-2-clutch-push-rod-seal.52590/

 

[Mailman]

By the way, I meant to comment on that beautiful bike of yours! Any more photos? Tell us more about it.

 

[Adamc]

Hi Mailman
Thanks for the replies and the links.
I will post more images and tell the story of the bike in another post.
Still getting used to the site, so hold tight.
Cheers
Adam

 

[Jim]

I will post more images and tell the story of the bike in another post.

 

[Adamc]

I am baffled. After removing the stator /rotor the main crank oil seal looks in good shape. No sign of any leak!
Anyone have an idea why the oil smelled of fuel and leaked out of the lower bolt below this; near the case locating pin?
A.

 

[Jim]

I am baffled. After removing the stator /rotor the main crank oil seal looks in good shape. No sign of any leak!
Anyone have an idea why the oil smelled of fuel and leaked out of the lower bolt below this; near the case locating pin?
A.

Pics?

 

[gggGary]

I am baffled. After removing the stator /rotor the main crank oil seal looks in good shape. No sign of any leak!
Anyone have an idea why the oil smelled of fuel and leaked out of the lower bolt below this; near the case locating pin?
A.

An educated? guess;
Cuz a petcock AND carb is leaking, it runs into a cylinder then drips down into the crankcase eventually thinning and overfilling the crankcase allowing the thinned oil to leak out through every oil seal. Parked on the sidestand the LH crank bearing/seal happens to be a low spot and right under where the gas would be dripping down from the bottom of the piston/cylinder.

 

[Adamc]

Hi Jim & Gary, I had a feeling you would say that Gary, so I have flushed the oil system and will refill with 20/50 oil.
If it leaks again I will replace all the LH side seals. Cheers Adam. (Pics Below)

 

[5twins]

It's pretty much a "given" that the clutch pushrod seal will need replacing. That's probably the #1 leaker on that left side. And I can see in your pic that you still have the red colored original in there. But there's a bit more to it with that seal. There's a bushing behind it that supports the pushrod and that's usually worn as well. If it is worn, a new seal won't work. The pushrod will wobble around too much and even a new seal will leak. See post #64 here for more details on that seal and bushing replacement .....

http://www.xs650.com/threads/200-special.51454/page-4

 

[Adamc]

Thanks 5twins. Yes you are correct; some wobble on the rod is evident, though no obvious leak. I have complete a seal set so will work through. Also check on the bushing issue as you sent the link. Cheers for the support.
Adam.

 

[5twins]

Well, it's best you clean that area under the cover really well and run the bike for a while, watching for leaks. A second common leak point under that cover is the countershaft sprocket seal. But many times the seal is fine, the nut holding the sprocket on has just come loose. It needs to be very tight, like 94 ft/lbs tight.

Also, your later model uses a two piece clutch pushrod with a ball between the two short rods. Older models used just one long pushrod. The short outer rod on yours is more prone to wobbling around, causing more and quicker wear to the seal and bushing. Most of us revert back to using the old style long one piece rod. It's much more stable and hardly wiggles at all. I recommend you search out an original though. It seems they skipped the hardening process on some of the aftermarket ones .....