This is the 4160. Holley Carb R75007-1
Yes. When I pulled the carb apart there were a number of cracks in the metering block, many that went all the way through. I got a new one from Holley and thoroughly cleaned the mating areas. All new gaskets on everything that had a gasket. I am pretty particular about cleaning. I spent quite a bit of time cleaning.
About an hour, and it was Chem-dip.
I have not even fired the engine since I rebuilt the carb. I want to make sure I have all of the initial settings correct before I start the engine and tune it properly. I put a new power valve and gasket in it. It is a 2.5.Rich running is common on Holley carbs, one of the causes is that the throttle blades at idle are too far open, exposing too much of the idle transfer slot. That slot should be a square shape, as seen from below the primary throttle valves. At idle you want it pulling fuel only from the idle system.
A blown power valve can also cause that, although I know that the 4160 Holley carb originally used by OMC & Volvo on the 4.3 does not have a power valve. Not sure if you have that same exact model #.
I don't think a V/P 4.3 should have 18* of advance at 600 rpm!
My old OMC gets set at 6*BTDC, full centrifugal advance at 3200 rpm is 12*, for a total timing advance of 18*. Yes much lower than the V8s, not sure why but that's how it is.
this is the carb used on the OMC and V/P 4.3s. No power valve.Holley 0-80492 600 CFM Marine Carburetor-Aluminum
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
Now you got me wondering if I stated the wrong brand. I read the instructions on it. I'll need to run out to the shop and take a look.
I will today. I need to get a tee and some vacuum line to get a vacuum source for carb tuning.
Thank you. I will check those.
I will take a picture of it when I get back to the house. I'm 99% sure I figured out what my fouled plugs problem was. The primary float was adjusted so badly that I don't think it could ever shut off. I've had about 2 inches of gas and oil mixed in my oil pan above the full mark. Also, suspiciously, there is a Mr gasket adjustable fuel pressure regulator between the fuel pump and the carburetor. According to Mr gasket, that is adjustable between two PSI and 6 psi. And they had it way down at 2 psi. I'm wondering if they tried to use that to stop the flooding problem. I just bought this boat this spring, and it had sat for a couple of years, and previous to that, it had a brand new engine in it. I'm just trying to cover all of my bases before I fire it up and fine tune the carb and the timing.
It is Gunk 96 oz parts cleaner. It says 20 minutes on it, so I left it in for 20 minutes.
Holley marine ought to have a welch plug in place of the sight gauge?
Nope, threaded brass plug unless someone installed that aftermarket clear plastic plugs ( not marine approved)
