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Jayc
01-05-2008, 10:19 AM
Its pretty cold over here in the UK right now (water temp just above freezing) and I'm having problems with the auto choke on my 84 S&S.

It only takes about 30 seconds for the choke to fully open which isn't long enough as it takes about 5 mins for the engine to be warm enough to idle without stalling.

How can I force the choke to stay closed longer?

TMCNo1
01-05-2008, 10:47 AM
Its pretty cold over here in the UK right now (water temp just above freezing) and I'm having problems with the auto choke on my 84 S&S.

It only takes about 30 seconds for the choke to fully open which isn't long enough as it takes about 5 mins for the engine to be warm enough to idle without stalling.

How can I force the choke to stay closed longer?

There is a 3 screw ring holding the black automatic choke housing on and there are notches on the carb housing indication settings and a point on the balck housing flange. Loosen the three screws and the black housing will rotate and IIRC, clockwise is richer/longer time, counter clockwise is leaner/shorter time. Hopefully a carb/choke specialist will confirm this, but you get the general idea.
30551

Jayc
01-05-2008, 11:26 AM
Ahh great seems easy enough. Will give it a try tomorrow.

TRBenj
01-05-2008, 01:48 PM
There is a 3 screw ring holding the black automatic choke housing on and there are notches on the carb housing indication settings and a point on the balck housing flange. Loosen the three screws and the black housing will rotate and IIRC, clockwise is richer/longer time, counter clockwise is leaner/shorter time.
Thats all true, but if the choke is set and operating properly, theres nothing you can do to increase the amount of time it stays closed. Thats not adjustable.

To set the choke properly, loosen the screws and adjust it so that its ~1/16" open when fully closed. The motor should be cold when doing this.

Jayc
01-05-2008, 03:13 PM
Any idea how long it should stay closed? Fuly open after 30 secs isn't enough time to get it warmed up. I'm having to run it at above 2000 rpm to stop it stalling.

rkmason
01-07-2008, 11:53 AM
Thats all true, but if the choke is set and operating properly, theres nothing you can do to increase the amount of time it stays closed. Thats not adjustable.

To set the choke properly, loosen the screws and adjust it so that its ~1/16" open when fully closed. The motor should be cold when doing this.


To slow down the opening rate of an electric choke you need to reduce the electrical current going thru the bimetal spring element by adding some external resistance in the circuit. I don't know if it's practical for you to do, but I would probably measure the resistance of the bimetal choke spring and add a high power resistor of the same resistance value in series with the choke coil. From that point it's just trial and error with different resistance values until you find a coil current that gives you the choke opening rate you need.

Chas
01-07-2008, 12:24 PM
Unplug it on really cold mornings.