Holley 4160 dripping primary main nozzle

After some research on the 'Net, I found it could be a leaking power valve. The Advance Auto Parts has them for $10.

The rebuilder put a 8.5" Hg power valve in my carb. Should I change it to a 2.5" Hg power valve?

Changing the PV should necesitate a jet change, too, right?
According to the PCM service manual, the 4160 with a 8.5 PV uses #582 jets. If I change to a 2.5 PV, should I replace the jets with #622 to flow a little more fuel since the power circuit will come in later?

Ok. If you don't ask the silly questions, then you end up doing silly actions. Not attempting to provoke a urination competition, but the jets and power valve do interact to some degree under high load, low vacuum conditions. The whole idea of the power circut is to allow you to jet lean, and have the power circuit add fuel when you need it.

By "ID of the PVCO" are you meaning "inside diameter of the power vavle channel orifice"?

I was looking at the PCM service manual hosted in the CCF reference section for a list # 7163 carb. It gives power vavle and jet specs.

I am by no means a carb expert, nor do I play one on TV.

Thanks for your reply, you probably saved me from my own ignorance.

Anthony

Yes, You're sortof getting it.

But, the there is no difference in flow between a 2.5, 6.5 or 8.5 PV is when at high load, low vacuum. ( as long as its less than 2.5")

My main point is one sets the mains (plus PVCO size) for full throttle. doinking with the mains for when choosing your PV opens is a crutch for improperly size PVCO's, and instantly gaurateed to eff up jetting at WOT.

If you have a marine carb ( a heavy truck 4150G), you are assured that holley set the PVCO's to the proper half the ID of the mains, for 25% more flow (unlike many 'universal' holley carbsthat were set too fat and belch smoke).

Setting the PV to when the engine needs the extra fuel with PV is a great way to fine tune the performance, But the mains are set and fixed using different methods and should not be adjusted to the PV. Jets are and early step in tuning, PV one of the latter.

To add to GottaSki's comments on Power valves. Even with a higher number PV like a 6.5 you'd be surprised how little you use it. Just for grins hook a vacuum gauge to your motor and go for a ride. On my boat the vacuum doesn't drop low enough to open the PV until over 4000 rpm so it's not even a factor in your basic carb setup.


If you have the stock carb that came on the boat I'd set the A/F properly and leave the jetting alone unless you can read plugs.

Well, it looks like I may have fixed my carb, as Joe Cocker says "With a little help from my friends". I'm lucky enough to have a neighbor that enjoys tinkering with anything that burns fossil fuels with cylinders in a V configuration. I took the primary bowl off and handed it to him. He took out the float, and cleaned the needle and seat out. He put it all back together, handed it to me. I put it all back together and fired her up. It idles like a champ now. No drips.   

It has been a few years on this but I had the same problem with dripping on port side at idle. And thought this may help someone.
At spring start up I did end up running it out of fuel.

I rebuilt the Holley 4160 carb last year and it ran fine.   

This year it ran fine until I ran out of fuel and then I Had the dripping at idle. witha really rough idle.
Pulled the bowl and metering block used carb cleaner and compressed air on all the parts and holes. .
Reassembled and had same problem.
Took it apart again This time I checked the screen filter where the fuel line connects, it was open on one side. So I assume some crap got in even though I have a spin on fuel filter. Fixed that.

The power valve and accelerator pump were fine. I pulled the float and held it under water, no leaking.
The needle looked fine but I had kept the old ones from the rebuild and decided to try one of them. Reassembled and it ran fine, no dripping at idle.

So the moral may be check/clean and then double check/clean

Thanks, I was running it on the hose working on it in the side yard. The gas gauge or sender is the next item to fix. That decided to flake out.

By the way took it out this weekend pulling kids for the Church youth group. Ran great. In fact idled so smooth I had to keep checking the tach to make sure it was still running. :-)