What do people use to adjust the mixture screw etc. on bike carbs in car applications, the screws are a right pita to get at and nigh on impossible with a screwdriver, need to get them something like on tune to drive to rolling road, and taking them off/on is getting a bind.

Which carbs?

The mixture screws on mine aren't too hard to get to.

My plan is to use an AFR meter to get the mixture right. I've balanced them with a Morgantune.

Stu

They're CVK's off a zzr1100, the mixture screw is underneath in a tube like housing.

Was thinking of making up some thumbwheels and extensions to solder on to the screws, but wondered if there were any other methods...

The air screws are only in use on tick over after that the main needles take over so if it starts and runs its not to bad
i/we just use a small screw driver

Yep, I'm trying to get a smooth tickover, with all cylinders working the same, balanced the carbs with a set of gauges.

It starts and runs ok now, a bit lumpy though, needs the final mixture / ignition map tweaking.

The rattle in my gearbox dissapears as soon as the engine smooths out, so another reason to get it right, hopefully won't need a box rebuild.

If it helps my air screws are 1 turn out but some people turn there's out 1-2 turns out
that's on a tuned pinto with zx9r carbs
Graham

Thats a help Graham, I'm at 1 turn out now, still think its a bit rich, Started at Bogg Bros recommende 3 turns out, it was so rich if I took the vac pipes off it ran better.
Cheers.
Pete

you say rich is that on tick over or when driving ?
The air screws are set for when you go to a mot my engine has to be under 3.5co and 1200 hc

i don't know what yours have to be

On tick over, its in a 72 mgb so only a visual check for emissions.

Test depends on which is oldest, engine or car, I just want it as right as possible to get to rolling road, its about 100 miles to Boggs.

Boggs are the best
when driving there the air screws will not be in use much the main needles are more important DON'T RUN IT TO WEEK it will melt PISTON'S just go steady and don't over rev it
I would recommend you ring Boggs for there advice before driving all that way
Graham

Sorry if i am telling you how to suck eggs

[Edited on 27/11/08 by jacko]

Hi mate,

I know these carbs relatively well,Your right the mixture screw is a nightmare to do in place,I had to remove carbs a few times until I got it correct !!

I just set mines as per Kawasaki settings,If you screw these to far out it will run to rich and you might find it wont take throttle between tick over and 2/3k rpm while under load,On these carbs This adjustment screw does alter the low down fuelling(upto 2/3k)
I know this as I spent most of this summer trying to get the fuelling right under all load conditions.I.E low down fuelling 2/3k rpm,3/6k rpm needle height and finally mains from 6K onwards.

If you need the mixture screw setting(as per kawasaki) let me know and I'll look out in the garge for it.

Cheers Mike

quote:

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I know this as I spent most of this summer trying to get the fuelling right under all load conditions.I.E low down fuelling 2/3k rpm,3/6k rpm needle height and finally mains from 6K onwards

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HaHa

Yeah I'll give you that,Really need to pay more attention whilst reading !!!

Mine were set up by Bogg Brothers and the air screws are 3 turns out. Dave pulled the carbs off to do it although I find them not to hard to adjust with a short screwdriver.

Needles a 1 groove below the middle with 1.8 mains. Runs perfectly with low co and hc.

Make sure there is a complete seal round the rubber diaphragm by checking all the slides move when blipping the throttle, then get teh balance spot on and they should idle real good.

My 1.8 zetec will idle at 500 rpm when cold no problem.

Steve

Thanks for all the replies chaps, looks like I just need to persevere, and get a stubby screwdriver in to do the little tweaks.

Sorry if the MGB bit caused confusion, its running a 1.8 blacktop zetec, on the cvk carbs....