Panhead case leak ffs

[leodavut]

Hi guys,

Searched but no luck.

I recently had my engine rebuilt, like 400 miles ago recently, and I've developed a terrible leak from between the cases at the front. I have attached a pic of the spot. It's literally pissing, did 75 fairly easy miles yesterday and lost about 250ml of oil.

Really can't be pulling the engine to split the cases and reseal so what would you recommend for a fix? oil and petrol resistant jb weld or similar? I'm thinking clean the area with a degreaser, brake cleaner or something and then smear some shit in the leaking area. any particular product to try? I see a few products claiming to be specific leak sealers, oyltite-stik was one. anyone ever used it?

Any ideas welcome and please don't tell me the only fix is to split the cases again I might actually cry.

Thanks

[JBinNC]

Looks like there is a crack in the right side case, below the threaded hole for the front case bolt. Yes, cleaning it and smearing something on the area is your best hope. I would choose something flexible, even, dare I say it?, silicone sealer. (Shudder)

Jim

[leodavut]

it's oil and road grub smeared by the wind and made to look like cracks, i nearly had a heart attack myself when i took the picture but i cleaned it all up and there are no cracks thank fuck. i was thinking about that, must be something somewhat flexible to withstand the vibrations i suppose

[Dragstews]

Really can't be pulling the engine to split the cases and reseal

Aaaaaaa errrrrrr .... Why not ??

[ExplodingCoffinEmporium]

You should do it right, split em. However not gonna say I didn’t JB weld a bad case on my 1992 CBR600 commuter 21 years ago that held up well enough to last me till I sold it 6 months later. In retrospect it worked but it was a bandaid.

When you say you had your engine rebuilt 400 miles ago what does that entail?

[47str8leg]

Are those mismatched cases ?

[leodavut]

Yes mismatched cases, but it didn’t leak before it was built.


Full rebuild, tear down clean, lots of new parts, new exhaust stubs, new inlets etc quite a big job by a reputable builder.

And I’ll need to split them eventually I’m sure, but I waited since February to get it back and have a summer of fun ahead of me! I just need to patch it up for the summer. Think I’ll try in weld

[farmall]

Reputable builder should reputably split that bitch and seal it decisively after dye checking the cases for cracks. Will the builder tear it down for you after riding season?

The teardown (they fucked up so your machine should move to the front of the line) of an already overhauled machine is not a lot of work and with fresh parts throughout the labor is pretty basic but that's the builders problem.

"Waiting since February" to get it back is nothing for these antiques. If any of your expectations for antiques are conditioned by modern bikes you're in for a rude awakening. I'd ride something else and get it sorted properly. If the leak is due to a crack I would damn sure want to find out immediately.

It's only a motorcycle. If you have Pan money in 2022 surely thou hast another bike or several to choose from during downtime. If not it's a fine excuse to add something more recent and reliable while the antique gets sorted.

The builder should be able to easily tear it down, fix the fault and have it sorted in a month if there's a crack to repair, less if not since he's already had it apart. For something expendable I'd scab patch it with aircraft fuel tank sealant after through cleaning with acetone but Pans are no longer expendable.

Decide how lucky you feel.

[Tater66]

Farmall is right. A good shop will do the right thing.

I understand wanting to ride. But at a cost of continual leaks and then out of pocket when you finally do whats best.



You could always run a screw with a rubber washer into it. I did that to a 55 Chevy gas tank and it held up for years.

[farmall]

A screw into a CASE JOINT??? That would deform both cases even more and need weld repair then machining or at least careful hand filing.

It does work for gas tanks though (before ethanol it was common to dissolve brown Permatex in rubbing alcohol to make expedient car fuel tank sealant and run sheet metal screws into the larger pinholes, I've seen it done though I'd just drop the tank).

[Dragstews]

[QUOTE=Tater66;858794


You could always run a screw with a rubber washer into it. I did that to a 55 Chevy gas tank and it held up for years.[/QUOTE]

Barkeep, No more for Tater, he's had enough ..

[pan620]

If you goop it up, put a screw in or what ever and take it back for repair under "warranty"you will probably be laughed at, have them fix it right, if you do not have another bike to ride....walk.

[JBinNC]

L,

Have you checked to see if that front upper case bolt is tight? If the threads are stripped in the case, that bolt ain't holding anything together. Knowing these old motors as I do, I would say it's a good possibility.

Jim

[Dragstews]

Kinda wild that the op is having this problem on a fresh built motor ..
Surely the builder would have not let it go out the door with stripped threads on a case-bolt ..

I have a wonder about internal pressures ... Breather valve timing, perhaps a restriction in the passages or the case vent hose ...??

[JBinNC]

Kinda wild that the op is having this problem on a fresh built motor ..
Surely the builder would have not let it go out the door with stripped threads on a case-bolt ..

I have a wonder about internal pressures ... Breather valve timing, perhaps a restriction in the passages or the case vent hose ...??

As much shit as I have seen from so-called "professionals" I would not be surprised.

And don't call me Shirley.

Jim

[Tater66]

Ok, that was a joke. Meant only to point out the ridiculousness of hillbilly repairs.

[Dragstews]

And don't call me Shirley.

Jim

You can call me anything under the Sun .... But late for "Supper" !!!

... /// https://youtu.be/qoYsfbq3vMc \\\ ...

[farmall]

As much shit as I have seen from so-called "professionals" I would not be surprised.

Ain't that why many of us got into wrenching in the first place? The good ol' days weren't that great if the only "Mom and Pop" shop in town turned out shit work when they felt like it, beat bearings onto crankshafts with a hand sledge, and held onto yer money indefinitely waiting to make a "minimum order" from equally uncaring distributors.

Quality shops deserve patronage so I do but there ain't that many quality shops. To be fair even experts fuck up now and then and only he who does no work makes no mistakes, but the measure of a professional is they own the oops and promptly make it right. The engine builder should be eager to get that bike back to sort it out because word of mouth makes or breaks high end shops. The vintage motorcycle community is surprisingly small.

A man only gets one reputation and that's worth more than a barn full of Crockers.

[Revelator]

I would give it a blast of brake cleaner followed with a light blast of compressed
air (maybe 30 psi) then repeat. then I would rub some (red) silicone sealant into the crack.
after it dries, I would spray a few coats of silver paint on it. but before I even do that,
I am going to check every case bolt for looseness.

[docmel]

Dont do shit to that leak. Take it back to the builder asap and let them see what you have. Any attempt to stop or fix the leak will just give the builder excuses that is wasnt his fault

But frankly, there arent that many "reputable" indies anymore. But thats just me. Regardless, give it a try

Again, take it back asap. The longer you wait the harder it will be to convince the builder he needs to make it right