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Discussion Starter #1
New to the world of CX500's and new to this forum. Just brought home yesterday a 1978' CX500 with 17,000 miles that hasnt run in years. All original non modified bike that is a little rought and needs to be completely gone thru. Need to see if I can sort out low compression in both cylinders, 60 PSI in left cyl and 90 PSI in the right. Hoping these numbers will come up once I get it running. I have wanted one of these CX500's for years and have been playing with older (90's) Harley's. Just finished a custom 97' Harley Sportster 883 Scrambler build in March this year and decided I needed another project. Originally I wanted to do a custom build with this bike but thinking about restoring it? Need to get it running first and then see how I feel. G.B.
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The low compression could be simple as poor valve adjustment or stuck piston rings or testing technique.

You are making a good choice to get it into running condition before any modifications.

At 17K miles, that bike is barely broken in. Likely only needs a good maintenance job.
 

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Discussion Starter #5
It just dawned on me after trying to look the bike over from top to bottom when I was buying the bike that I did not hold the throttle open when I did my compression checks. I just reran the test removing both spark plugs and making sure to put a little grease on the compression tester o-ring. With the full throttle cold I got 85 PSI in the left cyl and 100 PSI in the right. Still not happy with the 20% difference but it is what it is right now. However, the motor will definitely run with those numbers and still hope it comes up a little more after it is running.
 

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"However, the motor will definitely run with those numbers and still hope it comes up a little more after it is running." What he said. Get this done if you can before drawing any conclusions. But, check the WIKI for start-up recommendations after a long period of non-running.
 

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Keep it stock, at least until you can ride and find out if it wants any changes. My Standard is mostly stock, and there's little that I would want to be different.
while I agree for the most part, I've never had a bike tell me what it wants to be? BTW I had a 78 new off the showroom. still miss it.
 

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They are only original once, here is another vote for bringing it back to its former glory as opposed to customizing it.
 

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Welcome aboard! I grew up just North of Detroit. 11 mile & John R

That's beauty! I vote for Restore! Learn what you can from this bike and get an ugly basket case to customized.
 

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There are few good '78's left out there, and although I stay out of the whole "keep it stock!" debate, just want to point that out, if it were me, I would not chop it up.
 
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