84 720 with very high cold start RPMs

[5150 Wll]

Daughters truck has had this issue since we bought it.  Truck runs really well except on cold start the RPM is really high, I'd estimate at least 2500 or more, and this cant be good on a cold engine.  it's a stock Hitachi carb with everything hooked up properly and no vacuum leaks etc.  Is there an adjustment for the choke on this I'm missing somewhere?  I've done some searching and the only thing I'm finding is adjustment of the fast idle cam???  Any help appreciated.

[Tinman]

That IS the adjustment.  Small, hard to reach screw on the fast idle cam.

I had a similar idle.  Brought it down to about 2000 rpm.  Engine needs to warm up quickly, so don't drop it too low.

Edited November 12, 2018 by Tinman

[5150 Wll]

Thank You Tinman.  I thought that was it but wanted to ask first.  Appreciate the response

 

[datzenmike]

When the choke is engaged it also engages a fast idle. I would leave it alone as this speeds up the warm up and turns off by itself. There is no exact RPM for this, generally 1,800-2,200 RPMs. 

 

The fast idle adjustment is accurately set at the factory and almost impossible to get at. Very unlikely anyone has so it's fine where it is. You can bend the rod that engages the fast idle cam so the setting screw sits on a higher or lower step. Again it's sounds like it's working normally to me.