does anyone know the setting for the mixture screw on the solex 34/34 carb, as mine has been set at 8 full turns out, and the only setting i can find in the haynes manuel is 4 turns out so mine seems too much. I can`t get the carb to richen up and i think its running a bit weak.
I`ve just changed cars from a 340 1.7 to a 360 2.0 and is it me, but, i think the 1.7 was quicker ? or is the above problem behind this ?

I can`t comment specifically on this model carb, but generally speaking, it is difficult to give an accurate setting in terms of so many turns out from closed. This is probably a ball park figure given by the manufacturer in order that the engine will run and allow finer adjustment once it warms up. The finer adjustments depend on many factors unique to your engine, ie amount of wear or state of adjustment etc. etc.

If the book says 4 turns and yours is at 8, the chances are that it is as rich as it will go (think of undoing a tap!). If you are sure that it is lean , you may have an air leak somewhere in the inlet tract that is upsetting the mix after the carb.

Bear in mind also that the mixture screw generally only affects the mix at idle - your complaint that the car lacks power in normal driving, would be unaffected by this setting.

Maybe attention to other items such as air filter, plugs, leads, dizzycap etc. would help here. Having these in good condition will make it a lot easier to tune your carb - I`m sure the process has been described somewhere on these boards!

HTH

Will

Will's right. If you're that many turns out and you think you're a bit weak, plus driving problems are occuring something else is going on. I would suspect an air leak.

Search for lengthy posts on methods for finding them.

On cars of this age, all the moving parts wear out gradually, and it may well be that the carb moving parts are worn out, like throttle spindles etc and it may be time for a new carb.

setting for stationary also can have a tremendous influence on driveability with low throttle positions.

too lean would give a 'shaky' nervous cruising behaviour.

too rich has little influence, exept maybe for fuel consumption

Four turns out on the mixture screw is a basic setting to allow the car to be started, after this it's a matter of just fine tuning it to get the correct readings for CO and all the rest.

If it is at 8 turns out then I would check for leaks and such as the others have mentioned but also take out the mixture screw and check that the tip hasn't snapped off, if it has it may be stuck in the carb and this can cause a lean mixture whatever the setting of the mixture screw.

The idle bypass screw has a basic setting of 5 turns out and then it's just fine tuning required from this as well.

morgan105

Thanks for the advice, have searched for air leaks, but not found any yet, has anybody got experience of the two different engines, and what are your thoughts, cos my old 1.7 was smoother, but lacked top end, but my 2.0 seems slow and lumpy off the mark, but winds up to a fair old speed!
I am going to strip carb down over the next few days and check out jets, airways and float height. Engine has only done 57000 miles so i consider it only just run in ! Bye for now.

If in doubt, blame the carb. The CISAC 34/34 isn't a very nice design, and is prone to premature failure. Treat it to a rebuild and see how you get on. Consider an upgrade to a Weber alternative. Mine was a fairly good one, but magically all my problems went away when I fitted the twin carbs.

cheers

James

the weber conversion is the way to go , apart from mine coming loose just before Gaydon (last October / Novenber ) it has behaved perfectly and gives great performance and economy as my posts on other topics proove , You only need twin carbs if you have a little willy LOL

Didn't you have twin Webers on your....hehe....Rapid?!

cheers

James

not me , I never had a rapide

You had them on something...or are you lying to me, and it was a Rapid really? Nothing to be ashamed of...SteveP is a fan...ah...good point...

cheers

James

it was an estelle 130LSE with a stage 3 rally engine so it had a big willy and balls to match LOL

To paraphrase Husky, Volvo are the ones with the big willy for making an 2.0 'economy' engine which makes 138bhp with only twin sidedrafts and a mild cam.

cheers

James