I have tried to set up the carb as described in a previous post but i seem to be struggling to get it right,the bike is a montesa cota 200 with a amal carb.

The bike starts easily from cold using the choke and once warmed a little i then close the choke and unless i rev the bike it will stall i have tried screwing in the tickover screw slightly but then engine speed seems to be far too high.

Whilst i blip the throttle to keep it running the first little bit of throttle seems to cause a slight bogging and then the engine picks up and revs freely.

If i let the revs die and the engine stop the easiest way to restart is by using the choke even when hot.

I have started at the basic one and a half turns from fully in on the mixture screw but im not sure which way i should be screwing to do what?

The carb doesnt appear to be worn at all so hopefully that is not the problem and has also been thoroughly cleaned.

What position should the needle clip be in as a start position.

Any advice appreciated

If the air filter has not been oiled the bike will run lean.

welcome to messing about with old bikes..

getting the carb set up for slow running is easy once you know what to do

monobloc carb.. http://www.amalcarb.co.uk/documents/Click%...0and%20Tips.pdf

mk1 concentric.. http://www.amalcarb.co.uk/documents/Click%...0and%20Tips.pdf

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Edited May 31, 200917 yr by totalshell

Despite what you say it sounds very much like all the classic symptoms of a blocked pilot jet!

Tony

The rotation of the mixture screw depends on what side of the carb the screw is on, air-side or engine side.

If its air-side then screwing it in reduces air thus making it ''rich''

If its engine side then screwing it in reduces fuel thus making it ''lean''

If anyone feels I have got this wrong, feel free to call me on it...

And yes, it does sound like a blocked pilot jet, my advice is clean, clean again, and again, and again, and than one more for good luck....

I used a tin of carb cleaner and 2 strands from a thin wire rope, you probably shouldn't do this, but it worked for me.

Thank you very much for all your input.

I have stripped the carb down again this evening and as suggested found the pilot jet to be blocked so i gave the whole lot a good clean out again rebuilt and refitted.

Result, nice steady tickover and picks up nice and clean without any bogging down

Chuffed to bits

Thank you

I rode one of these in the '80's, the pilot jet would stop up at the slightest inclination, you could never see what was in there, possibly lint??, I always carried some spray carb cleaner to blow out the jet & passages, best improvment I ever made on the bike was to add a kehin round slide carb, I expect a mikuni round slide would be just as good

Cheers MotoVintage i will see how it goes on over the next few weeks as there are 3 filters fitted in the fuel line,one in the fuel tap,one midway between carb and tank and one in the carb itself.

Looking at the picture of your bike i see it has a front disc fitted,was this standard or did someone fit it as a aftermarket accessory

I bought the bike new, I added the front brake, but I am returning the front end to stock so I can ride twin shock events on it