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How to check the Spree choke

Posted: Sat Aug 28, 2004 2:07 pm
by noiseguy
From http://www.scootertherapy.com/nqchokepage.html
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This only works if the throttle is closed, as it operates on a separate air passage next to the throttle slide. If you open the throttle slide, no air is drawn through the passage for the choke. The wires heat a ceramic type heater that in turn causes the carb slide to drop into the carburator, turning off the choke. Putting current to the bystarter does not cause the choke slide to rise out of the carb, rather drop slowly into it.

Is it my problem? To test, remove the screws that hold the unit into the carb, and lift the choke slightly out of the carb body while cranking the engine to manually choke it. If it starts, then the carb is ok, choke is not

Checking the choke

Posted: Sun Aug 29, 2004 9:10 pm
by Jerry
Unplug both wires coming from the choke and going into the main wire bundle. Using an ohmmeter (VOM/Multimeter) check for continuity across the wires. The choke is actually a ceramic heater that heats up as current is applied. This heating causes the metal to expand and EXTEND the needle into the orifice and that cuts off the rich fuel flow.
When you pull the choke assembly out slightly what you are doing is manually choking the engine.
You can pull the choke assembly out, place on a bench and measure the expansion and contraction of the needle. Start cold (fifteen minutes at least ) Place the unit on a ruler or similar measuring device and tape down. Apply 12 volts from a battery and wait for five minutes. You should notice the needle is extended. Don't worry about the amount, it's small but visual on a measurement media.
These are very reliable mechanisms. Generally (experience) says the contacts on the wires are corroded or the carb orifice or tip of choke is dirty. Make sure the green wire grounds good also.

Posted: Thu Mar 31, 2005 3:43 pm
by darat
yep