Datsun 620 Help

[adams620]

My datsun 620 is over reving. I can press the gas a couple times real fast and it will sometimes go back down. Any help is appreciated?

[G-Duax]

Clean & lube the linkage, inspect for worn parts.
Which carb ?

Hitachi or Weber ?

[adams620]

Whatever came on it. It's always ran perfect but all of the sudden it started doing this. I ordered and replaced the choke thermostat thinking it was that. I guess the springs might be going bad.

[datzenmike]

 Warm it up thoroughly and take the air filter top off and look. Is the choke plate closed, part closed or fully vertical open?

 

If other than fully open, the choke isn't working right and likely the fast idle cam is on causing this.

 

If open, with engine off, spray all linkages on the rear of the carb with carb spray or WD-40. Hold throttle full open with a brick or something heavy and work the choke open and closed while making sure the fast idle cam moves into position choke closed and lifts up out of the way when open.

 

When at a fast idle, loosen the throttle cable... does it drop when loosened? If so it was too tight.

 

If fast idle cam off and throttle cable loose, the primary throttle shaft may be worn in the casting and the throttle plate cocking sideways in the barrel and not closing.

 

 

[banzai510(hainz)]

if its the choke one can take it off and wire it back., Its just a heated coil.I replace them with a manual set up if not working or asdjusted correctly.

 

This is pretty basic trouble shooting here . Like see if the cable is sticking(lube it up. or yes a weak spring but that is usually a given EZ fix

[adams620]

Guys I'm not getting any power to choke thermostat.  I've got power coming off the solenoid but then it stops. Does it have a capacitor or something.

[datzenmike]

The choke heater? This thing...

Maybe unplugged at front of carb?

It gets it's power from a relay that is only on when the alternator is charging (engine running)

 

 

What you can do is connect the Blue choke heater wire to the Red idle cut solenoid wire. Both will have a Black covering but are Blue or Red underneath. Both wires travel around to the front of the carb and can be jumpered together there easier. The idle cut solenoid is powered any time the ignition is on.

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