Uneven Tickover

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Aug 13, 2008
Just bought new amals for my 17,000 mile MK3 and cannot get a good tickover.The left carb cannot be set slowly enough on the throttle stop screw even though the cable has play at the top of the carb.The only way to slow it is to close the mixture screw but I thought this should be set to the highest idle speed to be correct-then adjust the throttle stop screw.Boyer is fitted along with the black air box and a new filter.When I get some sort of steady idle it is 1200 to 1400 and it will sometimes just cut out. Any ideas?
Sounds like the classic blocked idle jet. Try clearing that side with a piece of .0177 wire and blowing thru the hole. A piece from a wire brush is about right, needs to be at least 1.5" long.
It will happen even with new carbs if there is any c..p in the tank. Might have come with a blockage from Burlen also!

I have a set of new Amals on my bike.I bought them to cure the erratic tickover on my motor.They worked perfectly at first, but rather soon the slides began to stick in the bores! The surface of the slides were clogged with material from the carbbody, over and over.I cured that with some polishing, and running with a small amount of 2-strokeoil in the gas. I belive you might see the same behaviour from your carbs as they are new and tight.Todays unleaded gas adds to the problem.
Perhaps one of your carbs have a partially sticking slide ?
I would check visually that both slides sits properly with no throttlestops engaged. One other option is an airleak disturbing the idle.

I've had a similar situation with my new Amals. I started the bike for the first time in 20+ years (I think), and the original Amals wouldn't idle right. I sprung for a new pair (jetted for a stock 850), put them on, and have not been able to get it fully sorted.

I've replaced the fiberglass tank with a new steel tank, thanks to the garbage 'gasahol' they sell here. I've cleaned and rebuilt the petcocks twice, and built a new fuel line. Bike has new throttle cables which have been statically balanced.

I didn't think to do a teardown and check for blockages. I guess that's next.
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