'72 GT380 - Oil Issue, Well Maybe, ya'll tell me please

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jhood
On the street
Posts: 30
Joined: Tue Sep 22, 2009 7:59 pm
Location: Weiner, Arkansas

'72 GT380 - Oil Issue, Well Maybe, ya'll tell me please

Post by jhood »

I have just recently restored a '72 GT380 and had a few issues that I think have been worked out. After an initital startup and a run for 5 minutes I shut her down due to a non shifting issue. I should correct the shifting issue and the slight oil leak that was associated with it once I put her back together. Another issue was a mismatched crank gear and a points cam gear. I have since changed the crank gear that is thinner than the original so as to match it up with the plastic points cam gear that has a solid side facing the clutch cover. The gears do not mix and match. Apparently there were 2 types of gears used on the '72 380.

Now to my pending issue, I drained the oil after the 5 minute run and the oil was almost black. The color of the Yamalube that I used in the 2 cycle oil container. I used Castrol in the transmission. I had assumed that the SIRS check valve might be stopped up so I have cleaned it out and the port that it goes into. There was trash in it. My theory was that the valve might be stopped up and blowing the 2 cycle crank oil back into the clutch area thru the oil seal. The crank has had a complete rebuild by Bill Bune. I notice that running from the side of the oil seal on the lower half of the block is a small galley way that runs into a small type resivior on the top of the bottom crank case, which could allow this 2 cycle oil to run over into the clutch area of the block. Is this supposed to be the way it works to help lube the clutch or do I actually have another problem? All ideas will be greatly appreciated. Please help.

Thanks,
John
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