carb tuning

[phil63]

If one lifts the little button under the piston pot, the motor should rev up then fall back to normal tick over , but if the motor stops is that an indication of richness or weakness
Phil

[rayofleamington]

if the motor stops then that is a sign of weak mixture - with a rich mixture I thought the revs would rise a fair bit.

[moggyminor16]

mine cuts out when i do this ,so i trund tha screw thing under neith the jet ajuster well it made no differnt at all and it still giveing a good tick over but under load your better off pushing the car so off to buy a new needle and jet ,i have adjusted the screww all the way out and in but still no change so i recon it this problem but if you know any better please tell me before i blow out about £30 i think ,its had new plugs,piont rota army dissy, leads, coil so you can see i have had a lot done but still not working right
help

[Alec]

Hello MM,
jets and needles very rarely need replacing unless you have been hamfisted. Basic checks:- take off the dashpot and see that the piston moves easily inside the dashpot. The shoulder of the needle should be flush with the bottom of the piston. (it is held in with a grub screw and can be installed wrongly which will upset the mixture). Switch on the ignition and looking into the carburettor you should see fuel just below the top of the jet. If it is not visible then the float is cutting off the fuel too low and needs adjusting. Adjust the jet flush with the bridge then turn back twelve flats, that is two full turns, that is the basic setting and should not need much adjustment from there all else being correct. Replace the dashpot and piston and (aircleaner off the carburettor) push the piston upwards and release. It should slowly drop back down and you should hear a click as it stops.
If all is as above, start the engine and see how it goes. The lifting pin should only be lifted a fraction, not all of its travel, having said that I've never had any success with it myself. Before I bought some Colourtunes, I used to check the plug colour and listen to the engine to adjust the mixture.

Alec

[moggyminor16]

thanks for that info im just going out to try it will let you know how i get on if still the same maybe some eles has idears it has been off the road for about well since 97 sitting in a field and it the last thing to get right before the mot

[Willie]

If your car stood idle for such a long time you could well have
sediment etc somewhere between the bottom of the float chamber
and the outlet at the top of the jet. this would restrict the flow of
fuel so that you could probably tick over ok but lose power when
you opened the throttle. Can you start the car easily from
cold by operating the choke or is it difficult. When the engine is
warmed up what happens if you then pull the choke out?

[moggyminor16]

well just to let you know i went in the garage and found the colour tune i had yes ago and put it all on it was way way way way way off the reading being too rich i looked at the jet it had trun egg shaped so there for needed changing found one in garage that looked o.k put it on dune what you sead alec and it fired up like a dream took it on the trailer went to the old disueded airfield had it up to 50 in 3rd and 81 in 4th it seemed to have more in it but i ran out of room
so thanks all in the end it was the jet
moggyminor16
1966 traveller running again
1961 2 door saloon