Originally Posted by strad
This is a 1984 PCM 351 with the original 4160 carb and electric choke. This thing needs quite a bit of throttle to run during the initial warm up period. Once past that initial 1.5 minutes or so, it'll settle down and idle quite nicely if a bit on the high side (900 to 1000 rpms on the tach -- I need to adjust that).
I'm not convinced that the choke is operating the way I've read it's supposed to. It does operate mind you, just doesn't seem to go through the full stroke all at once or in a smooth fashion. How do I test it? Also one other thing. Do I need to re-jet this carb? it was originally run on the San Joaquin river delta (about 1-200 feet elevation I'd guess) and now I run it on Lake Mead (about 1100 feet elevation. It seems to run fine mind you.
Not sure how much you know about these chokes, but their supposed to be closed when cold and without power (which is the full choke position).
As soon as you turn on your ignition switch, power starts heating up the metallic coil inside that choke housing and it slowly starts opening the choke (gradually giving you less choke).
So, give you engine a few shots of throttle with ignition OFF when cold, then turn on the ignition and immediately hit the starter.
You can take your flame arrestor off and see if your choke's working properly.
If all that looks good, you may need a carburetor adjustment?