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Discussion Starter #1
I have a 305 chevy engine in a ski boat with a holley 650 double pumper mechanical secondary carb. Yes I know this carb is way too big for the engine, but I needed a carb and bolted on one I already had. When standing behind it idling, you smell alot of gas. I adjusted the two small needles located on the primary metering block, to achieve max vacuum. I had the idle down low and verified the primary butterflies were closed. Turning the screws had very little effect on the vacuum gauge. If my power valve was blown would it act this way? I also checked the float levels on both bowls, they were correct. The carb won't adjust out. Thanks.
 

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I dont have an answer for ya...and I'm not trying to be a ahole here but I hope this carb has been modified for marine use (the vent tubes curved to drain into the carb itself along with other changes) and is approved by the USCG for marine use cause if it isnt and the carb was ever to flood there is a good posibility that you would end up with gas in your bilge...not a safe situation to have in a boat

BTW what kind of ski boat?:)
 

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To answer the question a blown PV will make it rich. I know my outboard runs rich as heck with the muffs on it out of the water and it idles much higher too. No backpressure on the exhaust I think does it to mine. RM
 

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Discussion Starter #4
Yes carb has been modified, I installed some hose over the vents that if the floats stick fuel will be dumped into carb throat and flood engine out. Boat is a 82 model 22ft made by somerset. Just an old boat that works for now, till I can afford a better one.
 
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