On my wives 66 C10 I have run into a bit of a roadblock and I am not quite sure what the issue is, so I figured I would post up and see if anyone could help. She has a 66 C10 with a 292 I6, and the single barrel Rochester BV Carb. Recently we noticed a very strong fuel smell and after doing some investigating noticed the carb had fuel stains on the side of the carb where the gasket bowl cover is between the bowl and the bowl cover. I have only ever had this issue occur when the float gets stuck and doesn't properly close the needle in the seat like it should. After disassembling the carb everything looked fine, as it should be. Float was not stuck, had full range of motion, and the needle and seat looked good as well. Just for peace of mind I swapped out the needle and seat with a new one from a rebuild kit, and swapped the bowl cover gasket. But once back in the truck, it leaked again, and it should be noted, this is not like a slow seep, its a good amount of full, as if the needle and seat are not even there at all. Does anybody have any idea whats going on here, other than that the carb works great, and the carb was rebuilt just over a year ago, I can't imagine anything is seriously wrong with it. Can I be forgetting something? Any help would be greatly appreciated
There is a simple inline fuel filter before the fuel pump, which is mechanical. The fuel filter looks to be good.
Those leak between the sections, make sure they are good and tight. Go out and grab the top of the carb, give it a twist and you'll be able to see if its loose. You may need to replace the gasket between the sections though. I used to buy brand new 1 and 2 BBL carbs cheap, saved me lots of time and grief, worth looking into.
I tend to think float too. While you have it apart check the mating surfaces . Find yourself a piece of glass, lay some emery cloth on the glass and run the mating surface against the surface. The glass is always flat and it will true up both surfaces.
You can seal the hell out of the bowl cover gasket but the fuel level should not be running above the top of the bowl. Instead of leaking there, it will try to push fuel out of the vent tubes or somewhere else. There's something else at work here that's trying to put too much fuel into the float bowl. * Excess fuel pressure. * Damaged or sunk float * Misadjusted float level or float drop. * Dirty or sticking needle and seat, or seat loosened in the float bowl. If it was me, I think I'd want my fuel filter between the pump outlet and the carb inlet rather than on the inlet side of the pump. Is there also a small filter in the fuel inlet on this carb?
Some float links are more prone to be hung up than others. A good way to temporarily un-hang one is a sharp rap on top of the float bowl with a screwdriver handle. It works 90% of the time and will tell you if that is it, or not.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Float level set wrong has nothing to do with "Hanging"...
The top of the carb is really tight, I did replace the gasket between the sections but that should not even have fuel from the bowl rising that high. Thats what I keep thinking, the fuel level should never even reach the gasket. I am going to rule out needle and seat as I just replaced it even though it looked fine before. I have double and triple checked the float level per both the manual and the guide that comes with the rebuild kits, but the float could entirely be damaged, I am going to check this next, and I suppose its entirely possible that I have too much fuel pressure although its a stock mechanical fuel pump. it does have the small filter in the fuel inlet section. It is clean and thats why I have not been too concerned with the filter being before the pump. I can only set the float level properly so many times, but thank you for your angry response.
It almost has to be the float. If it's a metal one you should be able to feel gas inside it. If it's a foam type float, try putting it in a small container of gasoline and push it under to see if it floats well enough to put pressure on the needle. You could also try setting the float level lower. If it isn't a metal float, I'd replace it. Gasoline and alcohol tend to soak into the foam.
The needle and seat are in the bowl cover on this carb aren't they. If there's a "float drop" adjustment listed in the specs make sure it's set properly. And while you're at it give the floats a good shake and listen for any fuel sloshing around inside them.
You are correct, I am going to tackle it tomorrow, so I will report back here and let you know what I find. The floats are metal and I don't recall hearing fluid in them, but I am going to test to see if they will float properlly and also possibly set the float level lower and see if that fixes it.
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