P70 question and pictures

[struggle]

I have a guys P70 here and trying to vac test found two factory holes that create purposely leaks. One in crank to oil clutch bearing and one on top of block by cylinder. Once plugged it passes vac test. My though knowing what we do no about air leaks is maybe this isn't such a great design. I'm doubtful though moto seal will stay in crank though. Any experience on this?

Epoxy? What kind?

I tired moto seal but didnt like the way it set up as in the picture and put JB weld in it now on the crank hole. 3/32 drill bit I think fits in the hole.

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[alexcagle]

Jb is what I use in that hole too. Then just leave it in there. In my experience, the check ball inside the crank gets stuck and lets crap get sucked in, instead of only allowing oil out to lube the sprocket bearing.
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Is the other leak an auto decompression valve?
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Moto-seal works with gaskets, but don't
use it by itself as the base gasket delete.
It will leak, trust me. Yamabond 4 has excellent sealing characteristics for that. Hasn't ever failed on me yet.

 

[struggle]

The other leak is a little metal like cotter pin in a hole just below the cylinder. I put bugle gum over it while vac testing and found it leaking while pressure testing. Not sure what I will cover it with.


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[heimannm]

I don't know anything about the P70 but that cotter pin look a lot like the vent in the oil tank for many older saws. It there some kind pulse operated oil pump mounted in the oil tank?

Mark

 

[Modifiedmark]

Shane, that cotter pin is the oil tank vent. Not sure that it should be affecting a crankcase vac/pressure test.

The only way it could affect it that comes to mind off hand is if you have a leaking crankcase gasket..