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Thursday, July 9, 2015

Crankside Leak - UGH

I have had a ton of trouble with a leak from the crank area. This is bad because an oil soaked belt is probably going to fail. I have replaced the seal and spacer more than once and I thought that the time the pulley nut had loosened had caused some of my troubles, too.

All new stuff and good and tight. The little greenish line is nail polish I marked the front pulley nut with to inspect for loosening. The leak is this bad after 100 miles and just stopped long enough to get gas. UGH, UGH, UGH.

I'm not sure what to think at this point. I'm concerned the case insert might be leaking as shown here.

Pulled everything down and it looked like this. I really can't figure out the source of the leak. The area around the seal, spacer and crank are dry.

So here's how to pressure test.

First off, a fitting something like this. A timing plug drilled to take a nipple. Racepres lent me his.

Air fitting goes into timing hole.

So I did some looking for a spacer to take up the room of the rotor and pulley. The crank spacer has to be tight to seal. I used an 1 1/4 pipe coupling. It was 2 inches long and I should have bought the shorter one, but this worked fine.

On to the right side of the motor. The line that vents from the case to the oil tank needs plugged.

The regular crankcase breather needs plugged, too. I pulled the breather hose because I wanted to double check that this line wasn't blocked by debris or something causing high crankcase pressure.

I lowered the regulator pressure on my air compressor to somewhere between 5 to 10 psi. I blew into the nipple at the timing hole. The only bubbles I can find were from my front exhaust pushrod tube and rear intake pushrod tube. The insert was fine, the spacer to seal was fine, the spacer to shaft gap is about impossible to verify with the pipe coupling holding the spacer and seal together.

The plan is to silicone the heck out of the spacer and rotor meet-up and throw the breather gear back to the marks instead of the one off mark that the degree said was right.

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