Carb Leakage

[shoey949]

Well, I'm close to finished on my '82 Nighthawk project. I just recently rebuilt the carbs, including new bowl gaskets. I'm still getting leakage around a couple of the bowls, enough that it is quite a problem. If the new gaskets didn't fix, which I was planning on them doing, then what should
I do?

Thanks,
Nate

[kar_the_terrible]

What one of my friends did is buy gasket fabric from an auto store and cut a gasket for himself. That should be a suitable replacement, as its gasoline resistant and tempereature rated to a few hundred degrees (not that carbs get that hot anyway)

Alternatively, could your carbs be leakinig around the supply line? Im nont s ure how it is in hondas, but on some yams like mine, the fuel supply is through a banjo-bolt. If one of the washers is lose, you could have fuel from the carb bowls drip back out through the supply line, especially with the bike on the kickstand.

[shoey949]

any other ideas?

[TechTMW]

Are you sure the leaking is coming from the gasket?

If your needle valves aren't sealing properly ((weak springs, busted floats) your float bowls might be overflowing (There is an overflow outlet)

If the needle valves were notched on the part that seals the inlet, it could cause this problem also.

[kar_the_terrible]

Tech, on a related note: Do all carbs have overflow outlets for the float bowls? If so are the outlets easy conspicuous enough to detect

[shoey949]

all the floats are intact and non-adjustable. I just put in new needle valves and have had the same problem since as I have before.

[TechTMW]

all float bows 'should' have some kind of overflow, but since i've come nowhere near to breaking down every bike carb on the planet I couldn't say for certain. At any rate the most common kind of overflow on older bikes is just a brass tube that goes up into the carb from the float bowl.

Overflow is important so you don't get hydrolock from too much fuel entering the cylinder.

Anyway, Nate - There's only so much that could be causing a leak from the float - faulty gaskets, faulty needle valve, floats intalled upside-down or perhaps a cracked or damaged float bowl.

How is the mating surface of the float bowl ... Did someone try to pry them off or gouge them in the past?

[twowheelindave]

maybe a hair line crack in the bowl, or a bad needle and seat, split fuel line. Just don't do like my buddy did, and hit it with a rock.