No fitting for fuel pump vent tube

[a70eliminator]

New Holley marine carburetor, the original holley had a nipple pressed into the main body just below the air horn, new one does not, there's no extra cast to even drill the hole to use the old nipple.
Thought about drilling a small hole in the air horn but then the flame arrester would also need modification, anyone have a better less evasive idea?
1990 5.8 Cobra.

 

[Wroxbury]

Re: No fitting for fuel pump vent tube

wrong carb? If you have to modify it usually means it is the wrong part. Thats my experience at least.

 

[paultjohnson]

Re: No fitting for fuel pump vent tube

I would email or call hOLLY AND ASK wazzup wit dat ???!!!

 

[HT32BSX115]

Re: No fitting for fuel pump vent tube

New Holley marine carburetor, the original holley had a nipple pressed into the main body just below the air horn, new one does not, there's no extra cast to even drill the hole to use the old nipple.
Thought about drilling a small hole in the air horn but then the flame arrester would also need modification, anyone have a better less evasive idea?
1990 5.8 Cobra.

Some setups (like my previous OMC 460) used a tubing connection on the flame arrester.

The whole point of the thing is to route fuel into the carb intake so it doesn't get into the engine compartment.

I wouldn't modify the carb to do it though....

I can't think of any evasive ideas either......


Regards,


Rick

 

[Don S]

Re: No fitting for fuel pump vent tube

I usually just stick a small piece of steel or copper tubing (whatever is handy and the right size) through the fins of the flame arrestor so it's right over the choke plate.
Then 5200 it in place so there are no large openings in the flame arrestor around the tube. Now it will work just like the fitting did. Fuel goes into the primary throttle bores and will flood the engine and make it run bad, instead of leaking into the engine compartment and burning good.

 

[a70eliminator]

Re: No fitting for fuel pump vent tube

Well I bought the holley from a guy at work, it was new in the box, I swaped the jets and the secondary spring and performed all the adjustments specified for my engine, I did not notice the absence of the vent tube for the fuel pump until I went to install it, it must have been for an application that has the little glass jar at the fuelpump.
Anyhow I pulled the barbed nipple out of the original and did drill a hole in the air horn exactly where it needed to be, I tapped the tube fitting in place and applied a little -- cough caugh-- liguid steel, to give it some extra support. It looks like a pro job and worked out perfectly, heck I only paid 125 for a 4-6 hundred buck carb.

 

[Don S]

Re: No fitting for fuel pump vent tube

I tapped the tube fitting in place and applied a little -- cough caugh-- liguid steel, to give it some extra support.

I never put stuff that set up hard (liquid steel) where it could fall into a carb and into a cylinder. 5200 will at least give a little.

 

[a70eliminator]

Re: No fitting for fuel pump vent tube

Oh no you had to go and say that, well the molded up boss is on the safely outboard, if it doesn't hold it will just fall onto the intake manifold, the tube isn't going anywhere.
I'll try 5200 next time, hopefully there won't be a next time.

 

[HT32BSX115]

Re: No fitting for fuel pump vent tube

I only paid 125 for a 4-6 hundred buck carb.

You got a bargain! I got $150 for my Holley 4160 that was on the old 460!

 

[KRH1326]

Re: No fitting for fuel pump vent tube

My OMC v8 has the samo old Holley 4v with no fitting.

The carb sits on a 1" spacer that does have the fitting. Points aft.

Could a spacer have been 'lost' over the years?

Edit: Any intake vacuum port would do the trick.

 

[Don S]

Re: No fitting for fuel pump vent tube

Edit: Any intake vacuum port would do the trick.

I don't think I would do that. I would guess it would give the engine a vacuum leak for sure, and probably effect how the pump works.