Empty Fuel Bowl

[Jim Norris]

I have a 4150 HP.
I don't know much about carbs but, recently I removed the site plug in the primary side fuel bowl and noticed that the float was not visible. The fuel bowl was empty. I then checked the secondary side. It was not empty. I'm guessing that fuel should remain in the bowls and not drain away once the fuel pump shuts off. Am I right?

[PatBuckley]

You are correct, Jim.

There should be some evidence of leakage around the bowl gasket.

[Jim Norris]

Originally Posted by PatBuckley

You are correct, Jim.

There should be some evidence of leakage around the bowl gasket.

Pat, everything is dry externally, and there are no gasoline stains on the manifold. Could it be draining to the inside somehow?

[Calbullet]

Jim, is the fuel bowl low when your fuel pump is running, or is it low before you start up. If I let my car sit a couple days, when I first start, I can hear the fuel pump run and hear fuel fill the carb. I was told that heat from the engine compartment will evaporate some fuel in the carb bowls when you shut down .

Mel

[patrickt]

Jim, carefully idle the car with the site plug out on the primary side. Is gas filling up to the bottom of the hole?

[pusherfans]

I just upgraded to the HP4150 Ultra, which has larger site opening with a site glass. Mine The normal level on mine is midwy up the glass, maybe a little lower. this is where it is set when running. After shutting off (hot engine) and after sitting for few hours, I see no gas on the site glass anymore. The heat evaporates the gas. There is plenty of fuel in the bowls still, but just not in sight. You can buy clear plugs for your carb and it will help with float adjustments. On yours, it should be at th bottom of the site hole. I bet if you unscrew the lower two bowl bolts, gas will come out, even if it looks empty. The HP4150 does not have the lek down problem due to the air bleeds, according to Holley. Hope this helps.

ps. I am too new to ll of this, and I am no expert, the above I just learned in the last few weeks as I tweak my carb.....

ps # 2 - I refilled by bowls when the engine was stobe cold the next morning and left it alone all day and all night, and by the next morning, I could still see the fuel in the site glass.

Also, make sure you have some type of isolator between the intake and the carb to limit the heat build up. Without it, you could actually boil the fuel after you shut the car off.

[patrickt]

Originally Posted by pusherfans

... with a site glass.

PF -- keep an eye on the see-thru plugs. Over the years all the ones I've seen have not held up; they cloud up, crack, and leak -- I gave up on them a long, long time ago. Maybe they've improved them now, though.

[Jim Norris]

Thanks guys,
I turned on the electric fuel pump with the site plugs out and the float did rise so that it was visible, and the fuel level appeared to be at the bottom of the hole on the primary side and dribbling out of the hole on the secondary side. I suppose this is normal. It concerned me that one side remained full while the other appeared empty.
Is it critical that the level should be set while the engine is running?

[patrickt]

Originally Posted by Jim Norris

Is it critical that the level should be set while the engine is running?

Uhh, for those of us with mechanical pumps... yeah. Seriously, a lot of guys are just hesitant to do that with the engine running and you can do a pretty good job, even with a mechanical pump, by turning the engine off before removing the plug. But it sounds like there's nothing wrong with your carb.

[pusherfans]

I agree, your carb sounds normal. Also, if your intake is leaned forward slightly, like mine, it's prabably why you saw gas in one and not in the other, different angle?

I have an electric pump and the level does seem a little higher with the engne running than with the pump on and the engine off. Not enough to worry about through.

[Jim Norris]

Whew! Thanks again guys. I'll scratch that one off the list.

[Nor Cal Al]

Hey Jim,
The book that came with my carb said to remove the see-thru plugs after adjustment of float level and replace with solid ones. Like was said, see-thru ones leak after time.

Miss you guys....and my car.

Al

[Gaz64]

Originally Posted by Jim Norris

Is it critical that the level should be set while the engine is running?

One would think you can set your float level with just an electric pump feeding it, (engine off) but you'll chase your tail because the engine is not using any fuel.
You lift the float level up, dam it's too high, now you lower the float but the level doesn't go down.
It might even go up as you force the float to "sink" within the fuel. More so with glass windows.

[zrayr]

Originally Posted by patrickt

PF -- keep an eye on the see-thru plugs. Over the years all the ones I've seen have not held up; they cloud up, crack, and leak -- I gave up on them a long, long time ago. Maybe they've improved them now, though.

they haven't.

Z.