Poor Idle And Carb Balancing

[thomp1983]

Hi my L3 has suffered with a poor idle ever since ive owned it (since march).

What happens is the revs will hang at around 2krpm when slowing down then randomly at some point drop to 600rpm where it will sit until you move off then the process is repeated although occasionally the revs will drop properly to 600rpm straight away.

Now lately since ive fixed my blowing headers the bike will occasionally cut out at idle and is then a pig to start and does eventually normally after a bump start with lots of spluttering and the odd flame indicating the bike is running rich.
Today i managed to borrow a carb balancer from a mate so have had a look at the bike, the carb balancing was way out and i struggled to get a decent constant idle to set them with took alot of playing with the remote idle adjustment knob.

The minute i put the screwdriver on the end of the balancing adjustment screw without turning the screw the bike would start reving up, i assume this is not normal i suspect possibly the carbs aren't mounted in the rubbers properly and my pressure on the screw is opening air leaks.

After persevering ive got the carbs balanced roughly near each other the idle's still crap so i did a quick test of spraying carb cleaner onto the tops of the carb rubbers on all but the 4th one the cleaner caused the engine to rev up so there's definitely air leaks there.

Does anyone know how much new rubbers are from cradley?
Also is there a gasket between the rubbers and the engine?

Does anyone have any ideas as to why the bike has started cutting out just from fixing an exhaust leak?

The bike has stage 1 dynojet needles fitted with the rest of the jets being stock sizes i don't know what the idle settings for the carbs are set to though i assume they can't be far out as the bike goes well enough once going just at standstill it's hit and miss.

Also when on choke the bike revs up to just under 4krpm is this normal, makes a hell of a racket with the scorpion can on there.

Sorry for all the questions can find my way round a car engine happily enough but bikes are still abit new to me

cheers
chris




Edited by CaNsA :- To make for easier reading.

[Azazel]

Revving when you touch the screws is normal if you are putting pressure on them.

The screws connect to a shaft which is controlled by your throttle - if you press the srews the butterflies open letting more fuel in.

I'm having similar problems so let me know how you get on

[thomp1983]

just a quick update have done a fair bit of reading around and then took another look at the bike, it turns out im missing the rectangular gasket that's supposed to go under the airbox so im guessing ill have an air leak there, and the o rings on the carb rubbers have seen better days too but the carb rubbers seem ok so ill ring cradleys in the morning and take a trip down there if the stuffs on the shelf and im also going to pick up a colortune kit so i can see what the mixtures doing at low revs and see if the carbs are set right and ill update to let you know how i get on

chris

[thomp1983]

and another update, after a 150 mile round trip to cradleys i got home with a new airbox gasket and some o rings, turns out they've supplied me the wrong o rings, they've given me the ones that go under the plate the airbox attaches too not the ones that go in the carb rubbers so instead ive put the old o rings back in with some instant gasket, this seems to have cured the revs hanging my only issue now is the idles wrong so i need to look into setting it up properly which is a job for another thread so it seems my problems with the revs hanging were due to the car rubber o rings failing unfortunately there a weird size so you will need to get them from cradleys just make sure there the right ones, there on the top end microfiche not the airbox one.

chris

[cargo]

150 mile round trip ? ? ....................Cradleys post and it's nearly always next day.............................

[thomp1983]

unfortunately though it's saturday and as the weathers supposed to be good 2mrw i want to be out using the bike as we've probably only got a month or so of decent riding weather left. to be fair it only took a couple of hours just frustrating the o rings were wrong really should of took one of the carb rubbers with me but it's done now

chris

[razzcolio]

unfortunately though it's saturday and as the weathers supposed to be good 2mrw i want to be out using the bike.........
to be fair it only took a couple of hours

DEDICATION! lol!