Dauntless 225 high rpm's at idle.

[Supdaddy]

Hello. Great site and always very helpful. I'm not much of a forum poster type guy but value all the info I find here.
I have done so many searches for my problem googling just about every variation of my question but can't seem to find an answer.
Okay so here we go. A few months ago I pulled a '48 CJ2a out of the deep Maui jungle. It's been a blast bringing it back. I got the Dauntless 225 v6 odd fire restarted after a few weeks of workin on it. It started up and ran sounded pretty bad because the headers were rusted out. Other then that seemed to be running well. The other day I finally got my new headers and installed them and started up the motor. Sounds Awesome!!!! Only thing is it seemed to be running at a high rpm. I put a new guage on it and sure enough idles about 1200-1500 rpm. If I turn down the idle screw it will lower the rpm's but it will eventually die. So I have to keep giving gas to keep the rpm's up to keep it going. I checked timing and it was pretty out of wack. I adjusted it to 8 btdc not much change. The only new things on the motor to get it running were the plugs and wires rotor condenser cap and new points.
Any ideas why my idle is sooooo high? I mean the engine is running like a champ. No backfire no smoke no smell. It's better then I could have hoped for. Please help if you can. Sorry for the long post. Thanks.

 

[JR74CJ5]

You're along the right track...

Warm it up good, and make sure the choke kicks off. Inspect the air intake "butterfly's" and ensure they're fully open (not choked off still)

Adjust timing correctly with vacuum advance unhooked and plugged.

Then adjust the carburetor mixture screws. This process differs slightly depending on your carb model, but basically I'll normally turn the engine off, count the turns to get it all the way closed (screwed in - but NOT tight it will damage the needles if you go too tight) Remember the amount they were set at in case the below does not work... and start with 3-1/2 to 4 turns out (loosened) each - (On my carb there are 2 mixture screws which should be adjusted equally) Then start it. Start tuning leaner (closing / screwing in / tightening) each screw 1/4 to 1/2 turn at a time. When the engine starts running a little faster or developing a "miss" like syndrom, stop and turn it back out 1/2 to 3/4 of a turn (lean is nice, but too lean is too hot and starts burning thing up)

Then you can set the idle screw down to idling about 750 to 800 RPM or whatever works for you.

The above is very generic, and just how I do it... There are probably 100 ways to adjust and set a specific carb. Figure out which one you have (carb) and search more on it too for more things to look at.

I suspect either your choke linkage, or a vacuum leak is your problem, if still happening after you adjust the carb fully. There is a possibility you may need to rebuild the carb, or ensure clearances are correct on it too...