My leaking case halves

Finally. Been a few weeks now. I found the leak with oil die. 2000k miles on a complete tear down. I’ll be damned if I’d pull it back apart for a drip from a spot 3/8 long on the seam. Jb weld on a sanded clean service, sanded the repair down smooth then spray aluminum rattle can. The next owner when it comes time to rebuild can get it off with a wire wheel in a drill. Only chased the leak for a year. Oil die is the shit.

Mwood7800 said:

Finally. Been a few weeks now. I found the leak with oil die. 2000k miles on a complete tear down. I’ll be damned if I’d pull it back apart for a drip from a spot 3/8 long on the seam. Jb weld on a sanded clean service, sanded the repair down smooth then spray aluminum rattle can. The next owner when it comes time to rebuild can get it off with a wire wheel in a drill. Only chased the leak for a year. Oil die is the shit.

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Crankcase halves?

Are you saying the leak is from the case joint?

If so... Keep an eye on yer case studs... especially if you’ve had powder coating done...

Contrary to popular belief, IMHO the case joint should not leak. It has a wide surface area and plenty of studs to clamp the face tight.

Powder coating can ‘crush’ where engine / cradle fasteners mount, effectively making them loose, vibration and heat cycles will then create leaks in the crank case half faces. If not caught in time it this will also lead to damaged crank cases with cracks and damage around mounting holes.

Another factor in leaking case joints is the engine breather. Excess crank case pressure WILL find / force its way out somewhere. Reed valve breathers help.

The first thing I did was the 200$ reed valve. Didn’t help. Only would seep when the crank was throwing oil at the seam. Happy now. Hopefully a lasting cure

Is powder coating engine cases a thing? Seems risky.

Scout63 said:

Is powder coating engine cases a thing? Seems risky.

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Probably not. But powder coating of the frame and cradle, into which the engine cases mount, is.

Mwood7800 said:

Finally. Been a few weeks now. I found the leak with oil die. 2000k miles on a complete tear down. I’ll be damned if I’d pull it back apart for a drip from a spot 3/8 long on the seam. Jb weld on a sanded clean service, sanded the repair down smooth then spray aluminum rattle can. The next owner when it comes time to rebuild can get it off with a wire wheel in a drill. Only chased the leak for a year. Oil die is the shit.

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Kick the guy in the ass, who applied sealant & assembled the cases.
If it was you, get a friend to help.

JK, that’s a good choice to repair. IF it ever failed, it would only be a minor weep. I have JB Weld on the fuel petcocks of a 1973 vintage bike, been holding ten years now. Originally, just to “see if this engine is viable”, now it’s a curio.