new carb kit and wont idle?


Gear Grinder
Sep 22, 2010
North Salt Lake, Utah
Willys Model
Willys Year:
so i installed a new carb kit on my 226, it started right away but vary rough then it smoothed out a bit, this was with the choke on, as soon as i took off the choke it died, would start up again fully choked but wont run without it.
I was very careful to to replace parts one at a time so I believe it is installed correctly (i hope). A couple of things I noticed. the replacment needle and seat in the bowl were different, orginal had a sloid needle, new one was 2 peice with a spring, new seat had a extended tube, original did not. Also the new spring assembly included a keeper to depress the main spring, the original did not.
The last item, when i was removing the brass vaccuum fitting from the throtle body I defromed trying to break it free, I had plug that mathched the threads and used along with a soft blow hammer to get it straight, I know this is tied to the timing and this may very well be the cause, i plan to replace this but thought I would see if anyone had some insight.

Thanks guys.
Sounds like you have a vacuum leak. I would look at that vacuum port you were talking about messing up.
What happens if you crack the throttle to bring it off idle? If it is good, it's a vacuum leak.

If the engine will only run on full choke, it means you are not getting enough fuel. You didn't mention what carb is on your engine, but here's a couple things to check.

1: Make sure the idle mixture screw is turned out at least 2 to 3 turns. Turn the screw in until it GENTLY seats, then back it out counting the turns. Also make sure the idle mixture screw port is clean. Take the mixture screw out and blow compressed air or carb cleaner into the port. Then set the screw as above. If you have a 2 barrel carb there will be 2 mixture screws so do the same to both.

2: Be sure the float level is correct. The kit you got should have the settings in a table. If the float is too low it will make the needle shut off the fuel too soon and there won't be enough in the bowl.

3: Be sure you have the right carb base gasket. Some engines have a small round vacuum port on the intake manifold next to the big hole for the throttle plate. There is also a small hole in the carb base. Some carb kits come with 2 base gaskets, one with only the throttle plate hole and one with either the small holes or slots.

4: You will need to replace the fitting for the dist. vacuum line, but to test the carb, you can plug it off with some tape or such. Timing is usually set at idle with the vacuum line disconnected, so you should be able to start the engine and have it idle.

Last, the spring on the 2 piece needle is to cushion the float movement and is designed to let your Willys operate smoother on rough roads and radical angles when the fuel is sloshing around in the float bowl. It's actually a good thing and preferable to the one piece needle and seat.

If these simple things fail, you will have to dig deeper and recheck the accelerator pump function, metering rod settings etc.

Good Luck,
Old Willy
Ditto on the vacuum leak. Terry posted his reply as I was writing mine. If the engine will keep running at higher rpm or with the choke full on, spray carb cleaner around the base of the carb and other gaskets. If the engine speeds up, that's where the leak is.

I've got a '67 Fairlane with a 6 in it and one day out of the blue it wouldn't idle at all. I had my wife hold the gas pedal down and sprayed carb cleaner around the base of the carb. RPM's picked up with each spray. The carb mounting nuts weren't loose, so I pulled the carb expecting to see a torn base gasket. It looked fine. I changed the gasket anyway and the engine has been running fine ever since. One of life's mysteries.

Old Willy
Sounds to me like a plugged idle circuit in the carb.It's a very small passagway and maybe a small piece of dirt got in there during the overhaul?
Thanks everyone for the input, I will run down the items you all listed. I should have mentioned that it was running pretty well prior to the kit, it just had a flat spot as soon as you hit the throtle, I had to feather it and then it would rev, it idle fine also. I put the kit on hopeing to eleiminate the flat spot at the bottom.

Thanks again.