Holley carbs

[Timothy B.]

Three things on the carb of a 67 327/300 hp engine:

First, which type of bowl and metering block gaskets generally work the best? There is the more original one-time use type, and then there is the blue "reusable" types also. I have the blue ones on there now, but I can't seem to get the secondary bowl to stop seeping (doesn't drip, but is generally wet to the touch). What type/brand seems to be the most leak tight?

Also, when adjusting my two mixture screws, I have noticed that the drivers side ends up about only 1/2 turn out while the right side is about 1 1/4 out (when adjusted per service manual). Also, I can turn the drivers side all the way in to seat and the engine keeps running while seating the right side kills the engine right away? What is this a symptoms of?

Does the heat riser on the right hand side have any effect on idle mixture adjustments if I were to wire it full open?

[Clem Z.]

Re: Holley carbs

you will need to check the main body,metering body and the float bowls for warpage. if any one of these are nor flat and parallel you will have the problems you listed

[Joe L.]

Re: Holley carbs

Tim------

I anddition to what clem mentioned, I'd say that the mixture screw seats in the metering block have been damaged and so the block requires replacement. There is no practical way that I know of to repair these seats. Damage to the seats can occur for at least 2 reasons: the first is the corrosive effect of the scavengers used in the leaded gas which this carb was undoubtedly exposed to for many years. The second is from "klutz" mechanics who "hog down" the mixture screws as if they were tightening head bolts. The mixture screw seats are soft metal; the mixture screws, themselves, are steel.

You should cause no mixture adjustment problems, whatsoever, if the heat riser is wired open as long as the choke is fully "open" and the engine at operating temperature when you perform the adjustment.

[Timothy B.]

Re: Holley carbs

Well, turns out the leak that I thought was at the secondary float bowl area was actually one of the flat plugs on the secondary bowl assm., right next to the fuel transfer tube. This is the second one of the plugs that I have found to leak fuel, and since this is the pressurized part of the fuel system it leaks only when the fuel pump is operating. It appears I corrected the leak by lightly "re-staking" the outside of the plug area to tighten the fit on the plug.

Anyone know of a sealer that can be used to help seal leaking plugs like this one?

[Clem Z.]

Re: Holley carbs

i just epoxy them.

[Timothy B.]

Re: Holley carbs

Joe, thanks for the excellent and helpful responses. Last night I wired the heat riser open fully and started over with the carb adjustments just to see what if any difference it made. With the riser held wide open both mixture screws now behave similarly.

[Joe C.]

Re: Holley carbs

Tim:

Exactly like Clem said. Get it squeaky clean and use a clear epoxy. Funny that wiring your valve open had such a dramatic effect! Only way I can figure is if it was STUCK CLOSED before.