Floats on Holley 4BBL Carb.

[AaronWhitt82]

Re: Floats on Holley 4BBL Carb.

the one on the left is between body and metering plate- see the small hole above the large cavity? Use the one with the small hole. That is for the accell pump. The skinny gasket goes between the plate, and the float body.
The reason I ask to see other side of carb is- does your's have the pump lever at the back (secondaries) of the carb.
I seem to remember that the sec pump was always on the starter side. Is this carb new to you, or some-one else installed it?

Yea sorry I meant to exclude the fuel bowl gasket. I know what that is for, but that is how the pic showed it.
I still don't know why the primary had the other gasket with the larger opening on there and I'm not sure if it's ever been rebuilt before I bought the boat or if the gasket is stock from factory.
I'm getting to the point where I'm ready to throw this thing in the trash LOL
Not many moving parts on them, but plenty of gaskets and alot of tuning BS and I just can't seem to get it right!!!
I am pretty mechanically inclined, but carb's are newer to me..... First thing I've bought that has a Holley on it. I'm used to fuel injection.

I want to say that mine does have the pump lever at the rear of the carb as well.

This carb is not new. Came stock on this boat in 99 from Indmar. I don't know the history of it or if it has been rebuilt or had any work done to it.

 

[Coors]

Re: Floats on Holley 4BBL Carb.

If it's a double pump, I think you sec metering plate has the small hole also-check it.
In my experience, a double pumper even sucks in street race, and has no use on a boat. sorry. The cam has to be huge overlap to even take the shot; boats don't.

 

[Maclin]

Re: Floats on Holley 4BBL Carb.

The gasket with the small hole is definitely for the primary side metering block, it has to be that way to seal around the accelerator pump circuit junction holes between the metering block and the throttle body. If the other type gasket is used then some of the pump shot pressure will bleed off before it hits the squirters. It is also used on a double pumper secondary metering block because that secondary metering block has the accelerator pump circuit just like a primary metering block, just no idle circuits. I believe the gasket with the small hole can be used on any metering block with or without the accelerator pump circuit.

The accelerator pump circuit runs from the fuel bowl into the front corner of the metering block and into a channel that runs at an angle up to the middle of the block and exits thru a hole on the back side of the block that mates up to a hole in the throttle body. That hole feeds the channel in the throttle body that ends at the squirter fitting.

The shiny carb in the pics is not the same as the one you are rebuilding, you can tell because there is no secondary metering block between the fuel bowl and the throttle body. If you take that carb apart you will see it has a metering plate that screws directly to the back of the throttle body. The gasket for that is smaller than a metering block gasket and has a completely different shape.

I could not find the kit, we moved last summer and it is buried somewhere or gone, sorry!

Here is a pic of the carb on my boat, not my boat but the (Volvo) engine and carb is exactly the same. This is from the throttle side, primaries to the left and secondaries to the right. Metering blocks in both sides, notice the secondary block has no idle screws and no accelerator pump assembly.

 

[Maclin]

Re: Floats on Holley 4BBL Carb.

By the way Aaron, if you are really ready to throw it in the trash then please throw it into mine, Shipping is on me...!

 

[Maclin]

Re: Floats on Holley 4BBL Carb.

I left this out, the kits are almost always universal and come with all types of gaskets, even the metering plate ones. So do not think all of the larger gaskets have to be used somewhere.

 

[Maclin]

Re: Floats on Holley 4BBL Carb.

I lef this out also...The carb is more than likely a 735cfm or 750cfm model. Mine is a 735 and I bet yours is also. This is a very common carb on 350 cube 270hp performance boat engines from that era. Some 80's models used a Rocheter Quadrajet, then the Holleys showed up a little later from what I have gathered.

 

[AaronWhitt82]

Re: Floats on Holley 4BBL Carb.

The gasket with the small hole is definitely for the primary side metering block, it has to be that way to seal around the accelerator pump circuit junction holes between the metering block and the throttle body. If the other type gasket is used then some of the pump shot pressure will bleed off before it hits the squirters.

Alright, so I'm going to stick with the original one I have on there now from the kit, but I am going to change it for a new one because I cut out the notch in it to duplicate it to the other gasket with the larger opening.

The shiny carb in the pics is not the same as the one you are rebuilding, you can tell because there is no secondary metering block between the fuel bowl and the throttle body. If you take that carb apart you will see it has a metering plate that screws directly to the back of the throttle body. The gasket for that is smaller than a metering block gasket and has a completely different shape.

You have a good eye.... I guess I totally overlooked the pic and did not see that it didn't have a metering block on the secondary side..... So mine is the same as that one, but add a metering block on the secondary side lol

I left this out also...The carb is more than likely a 735cfm or 750cfm model. Mine is a 735 and I bet yours is also. This is a very common carb on 350 cube 270hp performance boat engines from that era. Some 80's models used a Rocheter Quadrajet, then the Holleys showed up a little later from what I have gathered.

Well according to Indmar when I called them they said their engines for the Moomba's in 99 came stock with the Holley 4150's 600 CFM so I'm not sure if that is their mistake or if it is 735 or 750. I also can't find that info out from Holley since they said the PN I gave them shows no record.
Mine is also 310 HP


Oh and if I decide to throw this thing out I'll def let ya know

 

[Chris_B]

Re: Floats on Holley 4BBL Carb.

I know this is a very old thread, but in hopes of resurrecting it...

My understanding of the larger hole in the center of this gasket is for the tube that for the accel circuit. The tiny hole simply won't fit around that hole. I just modified my gasket by cutting a notch that would fit around the tube.

 

[U2holic]

Re: Floats on Holley 4BBL Carb.

I have a 2006 Moomba with a Holley carb on it and it backfires each time I quickly accelerate Around 5-10 mph not, sure of the exact type model of the carb. Indmar chevy engine. Any ideas how and where I should troubleshoot?

I have pictures of the carb.