Motorcycle Repair: wont stay running, honda cx 500, leak down test


Question
I have a 1981 honda cx 500 custom. not the nicest of bikes but
shes mine.
I just rebuilt her. She ran fine for a week. now she'll fire up with
some time and aggrivation,  and then die.  petcock is on. she's
getting fuel. when i start her with a little throttle, she tries to run
like a dog, then dies. any suggestions? I'm all outa guesses.
-Jeff Buelow

Answer
Hi Jeff,

The narrative description only provides minimal information. It's difficult to diagnose the problem.

Check the appearance of the spark plugs. learn about reading the appearance of the plugs at NGK's website. "www.ngk.com" Maybe you've simply fouled a plug. In any case, clean or replace the plugs accordingly.

Perform a cylinder compression test to leaarn the condition of the engine. Fiollow with a leak-down test if compression readings are not within service limits.

Check and adjust valve clearances.

Check carburetor synchronization.

Respectfully,
Mark Shively