Rough running 1957 FLH

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Rough running 1957 FLH


Post by lesliewhit » Sat Feb 16, 2002 4:12 am

My flh was running great then backfired and started running on one cylinder.I checked the plugs and one was fouled and the other looked as if it was running lean.Could it be carb adjustment or bad valve.Any help would be greatly app.

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Re: Rough running 1957 FLH


Post by Cotten » Sat Feb 16, 2002 1:41 pm

It sounds like a classic intake manifold leak, the scourge of all motors!
Disassemble and replace your o-rings clean and dry, and then pressure test the manifold at ~10-15 psi with dilute detergent squirted around the clamps before you reinstall the carb.
This should be considered yearly maintenance.

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