Thread: Holley 4160 venturi dripping! Is it needle and seat

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Carb is on our Mastercarft ski boat with 351 indmar. Same as 4160 on car from my experience. Was rebuilt over winter and it ran perfect for the first 20 hours. Been running bad for the last 5-6 hours as I have been trying to narrow problem down. Starts perfect with idle air screws at about 3/4 out.
Had a car guy rebuild it, and could float be set to high? In these boats the motor sets on a pretty good angle, not like in a car. What has me stumped is that it was not loading up to start the season.....

Problem: Front drivers venturi is dripping constantly (a drip every second) and causing boat to run rich and almost foul plugs if i dont rev it while idleing out. If this motor were in a car it would be the front passangers side.

I have pulled the bowl to drain fuel and blown some compressed air through fuel line thinking maybe i had a small piece of crap in there. Did not solve problem. Have also changed fuel filter just as a precaution.

Have noticed that after I shut it off, it will continue to drip untill pressure bleeds off the fuel system.

If it sets a while, does not seem to do it upon the first startup. will run fine no dripping. As soon as we shut it down, switch out skiers, and restart it will start to drip again.

Thanks in advance for your guys help.

Brad

Check float setting first and Power valve/power valve gasket. Not an uncommon problem.

float level - trash in seat - too much fuel pressure. about the only things i know of. power valve, maybe but most new holleys have power valve protection.

denny you got it heat and the float setup is to hi if the power valves are bad they will drain thru the vacuum port side of the power valve thru the base plate were the blow back check valves go that will empty the bowls

Nitro, Denny and shine- thanks, these forums online always blow me away! Im amazed at how much you guys know. Dad has been saying float level, so he is on the same page as you guys. Sounds like it going to be "dad" knows best again. One day I will learn not to doubt the old man.

No sight glass on mine which is some of why im stumped. I know when I have reached my limit, and when to ask for help. Im there. No carb expert, but wrenched enough growing up that I know how they work and with a little guidance can fix it.

What is the secret to adjusting float on these carbs when you dont have a sight glass.



As for anti-blowback valve.... not sure if it was put in at rebuild or not?

Got it. Does not have the adj. screws. I got no issue pulling the bowl and adjusting it.

Will be next weekend before we get up to the lake to look at it. Will post results.

Appreciate it.