Oil Leak - Head Gasket?

Hey All,

I learned the hard way of why we do work ourselves instead of bringing it to a shop. Long story short -- I did the carbs (thanks to the church of clean) last spring. I busted a gasket and replaced all 4 on the boots leading into my head. Upon installing new gaskets, I must've missed a bolt on one of the gaskets and couldn't, for the life of me, figure out why my engine wasn't holding an idle. It turns out -- neither could the shop. So $500 later and stripping the head off the bike -- they found my mis-aligned gasket.

Now -- they returned the bike with a dent in the gas tank and a pretty serious oil leak. I rode the for about 2 months of summer/fall and the pictures attached are the result. I'm 90% sure the leak is from the head gasket and I just am looking to everyone on here for confirmation. The bulk of the oil is in between cylinder 3/4.

If I have to replace it -- should I consider doing anything else myself? The shop measured valve clearances and checked pistons -- they cleared everything under the hood. I'm not very mechanical and I'd like to avoid digging around inside. Is the gasket easy enough for me to replace?






Thanks,

PS -- the shop said the carbs were exceptionally clean and tuned perfectly -- thanks xjbikes

 

You did the carbs yourself?
Then you CAN (and should) do the other items.
What bike do you have?
Sorry to hear about the shop horror story.

Start with rechecking their valve clearance check (they should have given you a list of clearances at best, preferably a list of shim sizes and positions to go with it). You can not trust their work.
When doing the valve clearances you can inspect (and most likely) replace the valve cover gasket. The oil leak may very well be from the shop taking the valve cover off for their 'clearance check' and slapping it back on with no regard to condition of gasket and mating surfaces. Leaking from the valve cover gasket then travels downhill appearing to be the head gasket.

Try this:
http://xjbikes.com/forums/threads/airhead-valve-adjustment-with-pics.14827/

But before you go to far, get a comfy seat and a favorite beverage and read through this: http://www.xjbikes.com/forums/threads/the-information-overload-hour.27544/

 

I would almost guarentee that the shop did not get the correct head gasket set (there is a set or two out there that has a chain tunnel gasket that is too thick).

Degrease the engine, dust it with baby powder, and make sure of where the oil is coming from (besides the obvious leak from the valve cover gasket) If it's from the head gasket then get a new one from Chacal.

If the oil is only coming from the valve cover gasket, then it will run down and make it look like the head gasket is leaking.

BTW. The shop owes you a gas tank, or the cost of removing the dent and any associated painting that may be needed.

 

I just dropped the tank off today for them to deal with -- honestly I was hesitant about letting them do any more work but I suppose they can't dent it any more. Is there any way to find the source of the leak without a running bike? I have it pretty stripped down for projects.

 

Yup! I like to think I did a darn good job. I didn't replace any of the innards, just cleaned really well.

Sorry I didn't specify -- 82' XJ650

 

I'd have a neutral body shop do the work.

The only way to find a leak is to run the engine.

I hope that you don't have to pull the carbs back of soon. At the very least the float needles and throttle shaft seals should have been replaced.

 

Just saw this -- I kept all 4 carbs together because I was afraid of taking them apart after reading some challenges associated with getting them back in-line. I've taken them off, put them back and balanced floats so many times I won't mind taking them off to replace the float needles.

Throttle shaft seals scare me though....

 

Not as hard as it seems...............just more screws and fasteners to dis-assemble and re-assemble correctly. Lining up the carb rack isn't hard, it SOUNDS difficult but is really simple. Takes longer reading about it than doing it.

 

Here's the thing. You can replace the throttle shaft seals now, or later. The thing about doing it now is that you can plan the downtime.

 

Turn that fear into respect for paying attention to detail. Digital pictures while breaking the rack apart and little drawings and notes (if that is your thing), keep parts from each carb separate, note the orientation of the butterflies before removing, etc. etc.

 

Hey All,

Sorry to bring this back to life but I broke out the gasket set that the shop gave me after the job and found the gaskets in the attached image. Now -- correct me if I'm wrong because I'm a bit of a mechanical n00b but isn't that the head gasket and the little doughnuts that are supposed to go on after the head is removed?

 

That's the base gasket (goes between the cylinders and the top engine case). The red o-rings are for the base of the cylinders. The black o-rings are for the YICS passages in the head. The special-shaped o-rings are for the oil passages that are shared by the far-right studs. If those oil passage o-rings were not replaced that could be the cause of the oil leak.

I forget what the single, large black o-ring is for, but it's not for the head.

 

Don't forget NEW donuts for the valve cover bolts. If you don't get those, you're gonna have a new gasket that STILL leaks

 

So -- I was cleaning the bike with some degreaser, wire brushes, sweat and blood today and I noticed this:

I'm thinking maybe the oil leak came from here?

The odd thing is that the oil ended up on the other side of the bike. How is my bike even running with this gap?

 

That'l do it allright.

The valve cover just keeps oil from splashing all over and leaking out. The engine will run with a leaking gasket for a long time. It will even run without oil for about 20 minutes, then it will catch on fire and keep running for another five (there is video proof of this).

There are so many nooks and crannies in the cooling fin design that it's very common to find that an oil leak is coming from an area far away from whre the leak is noticed.

 

I hope your leak is a cover gasket issue... It is a simple fix. Unfortunately, it might not be coming from there. I have the same gap (see first pic). The new gasket doesn't follow the unique (sexy? heh...) outer curves of the head, but it sure does follow the "straight line" edge to make a positive seal with the cover. Look at the second photo I took from Big Fitz's post on checking valve clearances. First notice how damn clean his motor is! (I feel shame) Then notice the bump in the head that creates the gap that you see from the outside on your engine.

 

Darn -- thanks for the catch. Also, Darn to bigfitz.

 

I started her up today for the first time since November after some serious cleaning on Sunday. I believe there are two sources from valve cover gasket. So +1 to Stumplifter for guessing correctly. Anyway, thanks all for the help. I'll let you know if this wasn't the source.



EDIT: I didn't take a picture of the 2nd source but this seems to be the major one.

 

I'm back! I haven't fixed the Valve Cover gasket yet but I hope to get to that this week. I did some last minute inspection of the bike and found a very small amount of oil (despite the hideous picture) coming from the two front inner header bolts. My question is -- can the O-rings be replaced (as suggested above) without removing the head?

 

Still looks like oil is leaking down from the valve cover......