Float bowl overflow

I was running an errand and noticed I was low on fuel. Then, when I came to a stop, I smelled gas. I pulled into the plaza and popped the hood with the car off. Fuel was running out of the overflow on both carbs (dual HS2). Car would not start afterwards. I just would pump the fuel out the overflow. Towed it home and the next morning, it started up and ran fine. Any ideas?

Well, these floats can do that, and the smell of gas will be quite noticeable (and the offending float will be very wet). My guess is debris entering that float-bowl. Often the problem is poor and sticking Grose-jets, but crud can enter the lines and clog the valve only to come off.

I'd start with being sure there is no crud in the float bowl (and that you have a good, functioning fuel filter). Then, I'd check to be sure the jets aren't sticking (presuming you don't have Viton-tipped ones - if you have Grose-jets, I'd change them out). Make sure the floats aren't leaking through some sort of crack with gas entering one (such that it never floats up to shut off the valve). While there, be sure to make sure they are adjust properly (for shut-off).

Because you report this as intermittent, I'd go with crud in the system (so the valve never fully closed).

In my own case with my HS2s, the Grose-jets were the problem (and maybe a little dirt in there). They say that the newer Grose-jets have a film on them that can cause sticking (and I've seen it). The Viton-tipped ones work well presuming you are effectively filtering your fuel.

Agree with Mark, and if the car has been sitting for a while its not uncommon for varnish in the gas or what ever to cause this. You should have a fuel filter and a fuel pump that doesn't pump up too much pressure. I believe around 2 to 3 lbs is about right.

Kurt.

I drive it all the time but maybe let the fuel get too low and got some crud. I thought it odd that both carbs had the same problem. The carbs were rebuilt at great expense by Auto Sport in Seattle. I think they used quality parts, so I'll go with the crud for now. This is the first time this has happened, so it's not intermittent..........yet. The car has never run better than it has lately. Absolutely loving driving it just about year round these days. This just kinda dings my confidence in going long distances. I'm sure my wife won't be diggin' on having to load up the tow bar to come get me if this keeps happening. Ruh roh.. what if it happens on date night? :culpability:

I've heard some that elected to put a fuel-pressure-regulator, but if you have a standard SU electric pump (as many do), that shouldn't be a problem. As Kurt indicated, sometimes some varnish will accumulate in/on the valve (from gas sitting for a long time)... and then they get sticky (open). It's fundamentally a simple problem that requires a few steps to isolate and resolve.

This is generally a a needle and seat valve issue, you can remove the the float bowl lids bv pulling the fuel supply hose off and then removing the three screws hold the float lid on and there ya go, you got everything in you hand that can cause this issue, the needle and seat valve can be quickly acessed by removing the float hinge pin. It always good to have a couple of spare needles and seat valves, I prefer the viton tipped ones.

If it occurs on date night, tap the float bowls with a screwdriver handle. This often knocks the crude back down and allows the needle to seat so you can continue on to your destination.

Trevor Jessie said:

If it occurs on date night, tap the float bowls with a screwdriver handle. This often knocks the crude back down and allows the needle to seat so you can continue on to your destination.

Click to expand...

He-he, been there, done that