Holley 2 bbl !-302 ford

[Boomyal]

I was just running the motor, fast idle, after installing a new thermostat. After a few minutes the motor started running rough. I kicked the throttle up to 1800-2000 rpm and it smoothed out. Dropped it back to 1000-1200 rpm and it started running rough again. I noticed black residue floating on the water atop the cavitation plate so I pulled the flame arrestor and it was dripping gas down each bbl. I kicked the rpm back up, it smoothed out and quit dripping. I quickly throttled down to idle, while the butterflies were dry, then shut her down. After a couple of minutes I looked back down the throats and gas had puddled on the butterflies and there was still an occasional drip.<br />Any ideas? Thanks in advance.<br /><br />------------------------------<br />I'd surely rather be boatin than fixin!

 

[boat doc]

Re: Holley 2 bbl !-302 ford

If the fuel was comeing in the overflow tubes, (the ones that curve back into the venturi), it is a float / or needle seat problem. If it was comeing of of the bells in the ventrui, you have a metering block / metering block gasket problem. A quick fix that sometime works for a metering problem is to as you rev up the engine, start manualy closing the choke. Don't be afraid to get that sucker reved up past 3500 r's. Get it to the point you almost have that choke shut down all the way, but keep that engine running. It is scarry as hell the first time you do it, but I have it work almost 50% of the time. Also, be carful, and ready incase that sucker back fires, I hate to see ya blow yourself up.

 

[chris in va]

Re: Holley 2 bbl !-302 ford

Yup, I had the same exact problem with my 2bbl Holley/302. I was getting horrible gas mileage, and the thing was really hard to start. After taking off the flame arrestor, I noticed gas just pouring into the venturies with the engine off.<br /><br />Turns out the leaf spring that controls the bowl float needle (for lack of a real term) had bent down over the years and was allowing fuel to pour into the bowl freely, overflowing to the carb. <br /><br />It was very simple. Take off the bowl and bend that spring back up a bit, reinstall. I also cleaned out the assembly with carb cleaner just to be sure. Careful to put everything back together properly...

 

[Boomyal]

Re: Holley 2 bbl !-302 ford

B. Doc, by "bells in the venturi" do you mean those uvulae in the throat right above the top of the venturi? because that's where it was dripping from each one of those. there was no drip comeing from the curved tube above the choke butterfly, which I think is the float bowl breather. Any possibility of a ruptured powervalve?<br /><br />and thanks for your hint Chris, I will check that out. I assume your are speaking of the spring that holds the float valve closed.

 

[boat doc]

Re: Holley 2 bbl !-302 ford

Yes, I could not remeber the real name, so I thought bells would "ring a bell so to speak"<br /><br />usually when fuel comes out of those, there is a metering block problem. The problem could be trash in the metering block (which my choke trick will take care of), a split gasket, or if just rebuilt, the wrong gasket. There is a plate that covers that metering block on the back side, some of those plates are square, some of those plates are triangular (trapezoid) shaped. The carb kits usually come with the gasket of the triangular plate. A lot of people do not notice this when they put there carbs back together (cause it will still fit). If you have the triagle shaped gasket, on the square shaped plate, there are two holes that will not get covered up in the metering block, causing the same type of flooding.<br /><br />I have had a hard time finding those rebuild kits for a 2 barrel because the excelerator pump is like an 80cc, or 120cc sqirt (can't remember which size). If you cannot find a kit, you can use a 4 barrel kit, just be carefull not to tear that excelerator pump up.

 

[Boomyal]

Re: Holley 2 bbl !-302 ford

VIOLA!<br />It was a ruptured power valve. No one will talk to you about these problems. The parts houses don't have a clue and the mechs dummy up in hopes of getting your $110.00 to rebuild the thing.<br />Once I took the float bowl off and saw how clean everything was plus the float and needle valve were both good I took a gamble that the power valve was causing the problem. <br /><br />Thank you all for all the input. other opinions always keep the juices flowing.

 

[chris in va]

Re: Holley 2 bbl !-302 ford

That's good to know. I'll have to remember that if it ever happens to me.

 

[CRT Skiff Crafter]

Re: Holley 2 bbl !-302 ford

Hi Boomyal.<br />Been following you Holly post as I am in the midst of some issues that include the Holly 2bbl on my 302. Was there a physical inspection that verified the ruptured power valve or did you simply replace it and the problem vanished? Also, is a new power valve included in a rebuild kit and do you know of a good source for the rebuild kit?<br /><br />Regards, CRT

 

[Boomyal]

Re: Holley 2 bbl !-302 ford

crt, Ilooked at cut-a-waydrawing of the carb and the passage that the power valve screwed into led right up to the uvulae (air horns) hanging out over the top of the venturis. That was precisely where the drips were coming from. After disassembly of the float bowl and metering block and finding them spotless, I went to the local auto parts store and asked for a #50 power valve, the float bowl gasket and the meter block gasket. I reassembled the parts, squirted the bowl full of gas, thru the inspection screw hole, with a syringe and fired it up. Perfect. apparently all it takes is a backfire and maybe age to rupture the diaphram in the PV.<br /><br />Even thought the drips stopped (b4 repair) when I throttled up to 1800 rpm or so, it would have still been burning way to rich. My driveway was covered with black sooty residue that floated out on the water coming out of the out drive.

 

[Boomyal]

Re: Holley 2 bbl !-302 ford

ps, to answer your question directly, I guessed. I've never bought a rebuild kit but I do NOT believe a PV comes with it because there are too may different sizes of PV's depending on the application for that carb. Your local auto parts store should be able to fix you up. Either take the carb with you or take the tag # held on by a screw on the choke, or the LIST # actually cast into the carb. There are two different float bowl gasket choices. All of the meter block gaskets are the same. My carb is 28 y/o. The float bowl gasket ripped when I removed the bowl. The meter gasket did not, so I reused it and took the new one back. They weren't cheap.

 

[CRT Skiff Crafter]

Re: Holley 2 bbl !-302 ford

Thanks boomyal. Good info. Interestingly, I saw a cherry (totally original) 1950 Ford in the parking lot of a local restaurant today and was giving it the once over when the owner came out. <br />We had a discussion about engines and the power valve thing came up. He mention recently blowing one due to a backfire. I think I have the same problem. Adding to all the other things I have to do, I'll dig up a power valve as well. I'm gonna be very busy for the next week draining off fuel, rebuilding this carb and some other things I am still perplexing over. Hopefully I'll have a good week left in Sept. for playing on the lake. Assuming I get this darn thing running right. <br /><br />Regards, CRT.