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brexonn

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Was hoping someone could tell

Was hoping someone could tell me why the vacuum pressure from the hose going from the carburetor to the pcv valve pulses on and off on one engine and is constant on the other.
 
That's an indication of ba

That's an indication of bad idling due to your carb's idle mixture being off. It also might be a bad PCV valve. (Take it to NAPA and match it up. Cheap.)

I've started adjusting the idle with a vacuum gage since it's surprisingly difficult to set on a marine engine (that doesn't flop around on its rigid mounts). The trick is finding a vacuum source. Note: You can NOT use the PCV connection or you'll be way off!

Jeff
 
Thanks for your reply Jeff. I

Thanks for your reply Jeff. I switched the PCV valve and carburetor from the good running engine to the bad and saw no difference. Could a bad exhaust manifold cause these symptoms? Almost everything but the exhaust system has been replaced within the last few years.
 
"Hey, speaking of using a vacu

"Hey, speaking of using a vacuum gage to set mixture, where can I find a good old vacuum gage these days? All the car parts places only carry a wee little disco-gage meant for the dash. These little gages also try to measure boost too, so they are not very precise. All I want is an old-school vacuum gage from the days of carburetion."
 
"Harbor Freight, Jeggs, Summit

"Harbor Freight, Jeggs, Summit racing to name a few (on line).

No way the exhaust manifold alone is causing that problem, but if water is polluting that spark plug, that will cause rough running and PCV valve stuttering.

Jeff"
 
"Brexon

vacuum is effected


"Brexon

vacuum is effected from crappy idle,most likely spark related. check yer plug wires?"
 
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