Hi everone.Idrive an earley model 345 DL.I recently changed the carb to a late model 340.The little screw that turns the engine revs up or down has gone missing.The carbs are the same but the early screws are bigger than the late ones.Does anyone know if there is anything else icould use or has anyone got a spare. cheers Mark.

When the idle screw plasticy bit broke on my 1.4, I replaced it with a M4 nut, so could you use an M4 set screw? Been a while since I looked at a 1.4 carb though I'm afraid.

Thanks Cris i will give it a try. Cheers Mark.

Morning all,

Just to add a little detail:-

the idle speed and idle mixture arrangements are different depending on the model of Weber fitted. Up to and including the '83' B14, engines (designated B14.0E/1E/2E/3E) were fitted with a Weber 32DIR 93-100 or 93-101.

The idle speed was controlled by an adjustment screw in an air bypass drilling. This screw has a shaped end and cannot be replaced by a simple setscrew. This arrangement is shown below.



From the '84' year models (B14.4E) the carburettor changed to a Weber 32DIR 100-104. On these versions the idle speed is controlled by an adjustment screw and spring acting on the throttle linkage. This is "just a screw" and can be substituted by any suitable setscrew. See below.




The B14.4E remained in sevice on the UK market until the end but from the '86' model the Weber changed to a 32DIR 109. This was identical to the 100-104 but incorprated a small switch through which the idle speed screw passed - this was to signal "closed throttle" for the deceleration fuel shut off system and looked like a small, grey, plastic box with a wiring tag. (this is probably Chris's "plasticky bit").

If Marks carb is from 1984 or later "any suitable screw" will do - But you will still need to fit a tensioning spring to prevent inadvertent adjustment change.

Mac.

hello

I've noticed that the 1983 contact breaker 340 1.4 has a different carb to the later Renix cars. I recognize the changes here Mac described so clearly. The early carb was refered to as "constant CO"?

The vacuum pick up also moved during the '84 model year change.

Are the vacuum pick up location change, the idle speed change described by Mac and the change to Renix all one stage? ie all at the same time?

The black box on the inner left wing - is that the fuel cut off controller which closes the solenoid idle valve when the system notes the throttle is closed but revs are above 1700? (overrun condition).

that system would come in from '86 as per the throttle closed swtich installation introduction?

Yes,
yes,
yes,
yes,
yes,

Mac.

thanks mate! and thank you to Ev Zarifis who taught me that!

One further detail as far as the early carbs go, there is a base throttle stop setting to set the idle speed too, but if the carb is properly set up, then you shouldn't need to touch it.....however, what's the chances of one of these carbs having been set up properly and not 'fiddled' with by an eager techie?