Page 1 of 1

fuel pump/ carb

Posted: Sat Jun 17, 2006 7:12 pm
by maurice
hi there i'm having some trouble with my 1098cc as usual.
The fuel pump was ticking away like mad, even with just the ignition on. sometimes that stops (depending on whether i play around with the jet and float chamber float). but as soon as i start the engine the fuel pump starts ticking again. like a drum roll almost. it slows when idling but still occasionally decides to pump more and more fuel in. i've checked the dashpot piston and needle and it everything seems clean and fine. when i take off the air filter and look in to the carb when opening the throttle i can see a jet of fuel spraying up from below, and it looks like there's far too much going in. also got black spark plugs, and when i hold my hand to the tailpipe it gets wet and black, as if there's water/condensation coming out with black oily stuff in it.
any help appreciated.
thanks

ticking

Posted: Sat Jun 17, 2006 7:31 pm
by Willie
If the float chamber needle and seating is failing then you would usually get
excess petrol running from the top of the float chamber. As a first step, as long as the actual float is not leaking and contains petrol, I would fit a new
float needle and seating.

Posted: Sun Jun 18, 2006 12:28 pm
by maurice
cheers for that. i've had another look at the float and it seems fine. the float level also seems fine. I'm thinking it's more likely to be the jet/needle, because as soon as i accelerate, the fuel pump gets going again. i had the mixture checked a couple of weeks back, but i'm wondering whether the needle or jet got damaged since or something. are there any possibilities here?
cheers

carb

Posted: Sun Jun 18, 2006 3:20 pm
by Willie
As an assembly the jet and needle are really quite robust so I would still
start with the new float needle and seating and then carefully check the
float level setting as per workshop manual.

Posted: Mon Jun 19, 2006 10:59 pm
by bmcecosse
Car sitting with engine not running - ignition ON - fuel pump should tick once or twice - then stop. If it keeps on going then it's either sucking air or fuel is flowing past the float. Needle and jet are for mixture - test the mix when hot with the little lift pin - that's what it's for!

Posted: Tue Jun 20, 2006 1:23 pm
by maurice
cheers for your help guys. had some friendly men check the car and they managed to sort it. it seems that i had already fixed that problem, but the main reason for it running badly was that the dizzy was shot. rattling bits inside and a vacuum unit that was dead. so that's sorted.
anyway just waiting for the next problem now....

Posted: Tue Jun 20, 2006 2:09 pm
by Kevin
just waiting for the next problem now....
Dont wait for it get out and enjoy the smashing weather

Posted: Tue Jun 20, 2006 7:04 pm
by bmcecosse
Smashing weather ? It's pouring down up here in écosse land!!