air fuel ratio

[moosh2007]

arrrrrggggggggggghhhhhhhhhhhhh. can any one tell me what is about right number of screw turns for a good air fuel ratio?? standard 161 motor and carb. i cant get it to idle and its driving me Barry Whiteing crazy. i was told 2 full turns but yet still wont idle on its own?? is it a bigger problem than that?? played with throttle cable but seems tight etc

[misdablack]

might be your hoses bro. if theres a leak somewhere it wont idle

[moosh2007]

sweet, could well be they all abit tired. can anyone tell me where the air fuel screw should be to get a decent mix?? or proper mix

[gordo]

What condition is the carby in/ If you've rebuilt it, did you set the float height?
Check the ignition side is sweet, then valve clearances and check for air leaks - spray some engine start around the suspect areas.

Usual start position for an idle screw is indeed lightly screw it right in and 2 full turns out. If it's rich, there'll be a misfire that's a sort of muffled pop whereas a lean misfire is a sharper sort of crack.

If you're having trouble keeping it running long enough to adjust it, bump up the idle speed, adjust idle mixture till it's stable, drop idle and repeat.

[burntrubber]

Make sure the fuel cut solinoid is working it wont idle if that is not wired up or faulty otherwise just what evey one else said. If its the carb you will be able to tell whats wrong jumpy surging type of running before it stalls is to lean so either mixture screw wound to far out or some sort of block in the fuel side of the idle circuit. Sorta low pulsing idle which usually smells of unburnt fuel is to rich so it could be mixture screw to far in or a block in the air side of the idle circuit

[moosh2007]

thnks fellas. been doin my head in alot. shall begin my fixin tomorrow

[moosh2007]

cheers to everyone who contributed. running like a dream, combo of new plugs new air filter and some new hoses