carbon build up

Posted by Mark Graber On 2017/7/15 16:46:18

I had my 356 rebuilt about 2000 miles ago. While addressing a rough idle and some tappet noise I found:
1. way too much choke - adjusted, but still rough idle.
2. compression test revealed No. 8 is low. 90 on 1-7, 40 on number 8. Leak down revealed exhaust valve leak.

Pulled the head. I think this much carbon is excessive and could be the cause of the valve issue. No. 8 is gunked up the worst.

I'm attributing the carbon to the choke issue now resolved because:
I have a good mix of highway vs. city miles. Occasional 70mi highway trips.
Using a relative hot plug - Autolite 3136.

Do you folks think I am missing something here?

Thanks,
Mark

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