The odd thing is if you look on the Holley website, the carb that they sell as being set up for the OMC/Volvo 4.3 V6s is a 4160 that does not use a power valve but the main jets are bigger to compensate. I know because I have one, but I'm still using the Quadrajet on the engine at this point. Maybe this was changed when GM went to the Vortec heads?
All Holley Marine Carburetors are designed to meet Coast Guard specifications. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. The J-style vent tubes direct fuel/fumes back into the carburetor for safe operation while on rough...
www.holley.com
Whil
The odd thing is if you look on the Holley website, the carb that they sell as being set up for the OMC/Volvo 4.3 V6s is a 4160 that does not use a power valve but the main jets are bigger to compensate. I know because I have one, but I'm still using the Quadrajet on the engine at this point. Maybe this was changed when GM went to the Vortec heads?
All Holley Marine Carburetors are designed to meet Coast Guard specifications. A marine carburetors fuel metering system is calibrated to compensate for unique engine loads found on boats. The J-style vent tubes direct fuel/fumes back into the carburetor for safe operation while on rough...
www.holley.com
While it doesn't say it on this part of the website, if you look up this carb in the spec data elsewhere there is no power valve and I can tell you having had the bowls off there really is none!
PS, either your thermostat is sticking and not closing all the way or there is a flake of rust or sand in the seat preventing it from closing. Normally that engine should run right at 160, maybe a little lower after getting up on plane and a little higher after coming off plane.
Hey Lou C. I appreciate your research. But the cold reality is my carburetor, volvo penta part number stamped on the throttle body is 3857046. The part number was superceded by 3858333. And it does, in fact, have a 5.0 power valve. Also, both the OEM rebuild kit - 3854341 - and Holley renew kit - 703-29 - come with a power valve, the Holley with a 5.0 and the one I used (3854341) with a 2.5 power valve. So, there's no denying that this specific carburetor HAS a power valve - and that apparently per both the Holley and VP/OMC carb kits which both contain power valves - it was designed to have one...just saying. Now, is it possible that an owner of my boat prior to me removed the power valve, threaded a plug in the hole, and increased the jets by 6 sizes? Maybe. Since you state you have the same carb with no power valve but larger jets, what are the size of your jets ( I didn't check the size of mine before reassembling)? And BTW, I tested the 5.0 power valve that was in my carb with a vacuum pump and it would not hold vacuum. I've ordered a replacement 5.0 since I'm still getting hesitation with the 2.5 that came in my kit.
And I'm going to pull the thermostat and test it since some of my symptomotology could be related to an engine running too cool. Thanks again.
e it doesn't say it on this part of the website, if you look up this carb in the spec data elsewhere there is no power valve and I can tell you having had the bowls off there really is none!
PS, either your thermostat is sticking and not closing all the way or there is a flake of rust or sand in the seat preventing it from closing. Normally that engine should run right at 160, maybe a little lower after getting up on plane and a little higher after coming off plane.
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