Fuel pump

Dasher · Post by **Dasher** » Mon Jun 18, 2012 8:30 pm

I have a problem with an 89 Brumby in that it began stalling when slowing down. It stalled today coming down my drive and when I stopped I could hear a bubbling sound. Turns out the carburettor was full of fuel, like highly pressurised. there was petrol coming out of nearly every place possible, sorta like the there was too much pressure for the needle and seat to stop fuel from coming into the carby. What stops the fuel pump from pumping? Could my fuel pump be faulty or what is causing the high pressure in the carby

steptoe · Post by **steptoe** » Mon Jun 18, 2012 8:51 pm

How is the return line of the front fuel filter?

Or blockag of the breathers of the pollution cannister ?

Dasher · Post by **Dasher** » Mon Jun 18, 2012 9:06 pm

Return line is fine, there was no fuel coming from there, it doesn't make sense. It doesn't have a charcoal canister fitted. It is an 89 model but is fitted with a rebuilt carby from an early 80's wagon.

YouTube · Post by **El_Freddo** » Mon Jun 18, 2012 10:32 pm

Pull the top of the carbie off, remove the brass valve that the float actuates, remove the crud from in this valve, clean out any other crud in the carbie, put it all back together and replace you're fuel filters.

If you had fuel coming out everywhere it's usually due to this little valve not being able to close, or your float has a hole in it (in which case it's no longer a float

)

Cheers

Bennie

Dasher · Post by **Dasher** » Mon Jun 18, 2012 11:10 pm

The carby has just had a kit in it, had an acid bath etc so it was spotlessly clean when I put it on a week or so ago. I am wondering if the 89 plunger type fuel pump is pumpIng too much fuel for an 83 model carby. If that was a problem is there a fuel pump available that would fit straight on that pumps less. I just don't know? When I took the air cleaner off after it last stopped it was full to the top of the choke with petrol.

Thanks for your thoughts

Dasher

steptoe · Post by **steptoe** » Tue Jun 19, 2012 8:47 am

OK, Bennie sounds correct. I once did my first carby rebuild, took it for a test drive down a long windy road on the edge of town and found myself walking back. The car stopped, carby flooding with fuel caoming out from everywhere. The return was with a spare carby to nab its float. The float in the first rebuild was brass, had a split (me?) and with some time took on enough to sink it just holding the float valve open.

Post by **TOONGA** » Tue Jun 19, 2012 9:58 am

does the carby have a brass float or one of those black plastic floats?

was the needle and seat put in / adjusted properly?

either float type will look fine but once in the carby can fill with fuel and not work properly, or be adjusted so that the needle never shuts filling the carby with fuel. the float could be jammed in the carby as well causing it to not do anything.

An 89 brumby should have a fuel cut off switch so when the ignition is turned on the fuel pump primes then stops, is this happening or is the fuel pump constantly running?

you say there is no charcoal canister, what else has been changed on the engine?

pictures of the engine bay can be a big help.

TOONGA

Dasher · Post by **Dasher** » Tue Jun 19, 2012 10:17 pm

Thanks for your replies fellas, I've had the top off the carby today and everything is fine, it's the black float type buts it's sound and there is nothing in there, clean as. The level of the float is correct and all, it seriously has me beat. When it was overflowing with fuel I took the return fuel line off and there was nothing in it, no pressure at all yet fuel was bubbling out of the venturies.

Point · Post by **Point** » Tue Jun 19, 2012 10:28 pm

if you don't have the charcoal canister hooked up does that mean you've blocked up all of the fuel tank breather system? If there's nowhere for fuel tank pressure to vent it will likely push fuel out. Have you checked if the return is blocked?

Dasher · Post by **Dasher** » Tue Jun 19, 2012 10:35 pm

I should also have said that the whole charcoal canister system is gone. The only hose going into the Carby is the fuel line, the return line goes back to correct place, there is the vacumn line to the dizzy and that's it. The crankcase vent jigger goes into the aircleaner as do the rocker vents, there's nothing else.

Dasher · Post by **Dasher** » Tue Jun 19, 2012 10:45 pm

The tank vent line is not blocked, it's fine and the return line is clear, I've had the compressor through everything and it's all clean.

steptoe · Post by **steptoe** » Wed Jun 20, 2012 8:12 am

still doing it ? Or you looking for a problem ? Wonder if you tried it without fuel tank cap to dispel any unwanted pressures from tank and no charcoal canister suggestions ...... You have, or someone, swapped carbs ...is the fuel bypass T fitted up close to carb still in the fuel supply line ?