Holley 4150 issues

[snowdan]

SO I have a holley 4150 on a 454 just rebuilt the whole carb because when got the boat you could see where gas had been leaking on to the intake manifold. Engine wont start and getting white smoke out of the top of the carb along with some fuel? Also the rod for the butterflys is leaking fuel when I pump the throttle? Is this carb shot? I hand cut all of the large bottom gaskets with the thickest gasket material I could find to try and stop the leaks but to no avail. Wondering if there is something else I can try? Also only cylinders 5,6,7,8 are getting wet maybe because the carb is leaking?

 

[RogersJetboat454]

Re: Holley 4150 issues

It's possible that there may be excessive clearance in the throttle plate around the shafts for the butterflies.
As far as leaking fuel, did you set the float height correctly? Is it leaking up and out of the vent tube into the barrels, or is the leak from down below? You didn't use a carb rebuild kit, and cut your own gaskets?

 

[snowdan]

Re: Holley 4150 issues

No I used a 4150 rebuild kit. I cut the gaskets on top of and below the base plate as well as the gaskets for the riser to the intake manifold with a thick cork gasket. It is leaking on the outside of the carburetor on the both sides of the primary throttle shaft. Just checked the shaft and there is play in it. I did set the float heights when dong the rebuild while the bowls were off. I am also not sure if this carb is marine or auto? I have read that marine will have the j-tubes but have also seen marine carbs without so unsure. Maybe I need to replace the base plate? Or maybe just the whole carb? How can I determine its cfm? or How big of a carb I need?

 

[snowdan]

Re: Holley 4150 issues

Also just found that the list number of 4779 on a holley is a automotive application. The guy on the phone said alot of people use this in marine applications? However to replace the base plate is 150 plus and a new carb is around 450. Just know that with the fuel leaking like it is the boat probably wont start.

 

[RogersJetboat454]

Re: Holley 4150 issues

I have a feeling this may have been an automotive carb plunked on it, but maybe one of the OMC guru's can check the list number to see if it's legit.

Just out of curiosity, is it mechanical secondaries, or is it vacuum secondaries? If it's mechanical, I should think chances are high it wasn't put there by the factory.

 

[Boomyal]

Re: Holley 4150 issues

As far as I know, Holley never made a 4150 Marine Carburetor, so I think Roger may have hit the nail on the head. Holley Marine Carbs were 4160 models. Regardless of what 'the guy on the phone' said, automotive carbs should never be used in marine applications.

 

[FourWinnKC]

Re: Holley 4150 issues

I have a Holley 80378-1 4150 series 750 vacuum secondary on my King Cobra 454. It's the original carb.