I have a Mk4b with a Amal Carb thats running a tad on the rich side (black plug and a bit fluffy mid revs)

Cant remember which way to turn the mixture screw?

air screw is tick over only,so wont be that.lower the needle one slot.

Air screw is mixture - in for rich, tune from rich to weak. Throttle stop screw adjusts tickover speed. As above it may be the needle position at higher revs but the pilot mixture can have an effect surprisingly high up the rev range if well out.

This is essential reading http://amalcarb.co.uk/downloadfiles/amal/amal_tuning_guide.pdf

Thanks for the replies, I have just bought the bike and it might have been richened to make it easy starting.

couldn't remember if it was tighten to richen or weaken? and maybee lower the needle as there might be some wear on it or the main jet, but will give the guide a bash. Can you still get Amal parts ?

Cheers

Dave

yes you can get pritty much all the amal parts try burlen ltd

Thanks for the help Guys, have now fitted new needle and jet , replaced main and pilot jets as they were a bit claggy. Now have a strawberry coloured plug which shows its running correctly and its also pulls like a train, now a pleasure to ride. Well pleased even if Burlen were a bit slow in sending the parts out ( 3 weeks).

Cheers

Dave