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Discussion Starter · #1 ·
Ok, it was suggested that I ask this question here, so, I inherited a 72 sportster that had been sitting for a long time and I just got it. I did a compression check on it after warming it up good. It came out 165 lbs both cylinders, Does anybody know how that stacks up with stock 1000cc of that vintage?
Bob
 

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I had a 74 and worked on a few friend's bikes back then. That 165
sounds about right. It's also important that the pressure measured is
close to each other in both cylinders.

Back then, the valve guides/valve stems would wear prematurely from
excessive galling. Two brand new 74/75 Sportsters we bought had
valve issues within 2000 miles. It seemed that the metals used were
not compatible. We would install new different guides and valves and
they were good to go then. I think we did five or six bikes total then, that was a long time ago...

Good Luck!
 

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Discussion Starter · #3 ·
Thanks for the answer Duckman. This bike had the whole top end redone about 5 or 6 years ago, but; never got any run time after that. When I got it from my Brother-in-law I did some work to get it running, battery, bendix, carb rebuild, oil change, reseal tank, fix a couple of gasket leaks, replace a gunked up advance mechanism and so on. At first it ran ok, but; was smoking some and had quite a bit of blow-by from the gear case breather tube. Since I have gotten it running all that seams to be improving that leads me to believe that it just needed to be broke in and that the rings just never had a chance to seat. The 165 lbs is in both cylinders. Thanks again for the answer,
Bob
 

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Ok, it was suggested that I ask this question here, so, I inherited a 72 sportster that had been sitting for a long time and I just got it. I did a compression check on it after warming it up good. It came out 165 lbs both cylinders, Does anybody know how that stacks up with stock 1000cc of that vintage?
Bob
Very good if that is an un-touched engine.:thumbsup
Scott
 
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