4100 autolite help

[jopizz]

There's never been a check ball in the secondaries on any 4100 I've ever taken apart. Can you show me a diagram that shows it.

John

[davidmij]

Hey John, if you look on page 2-25, figure 13 in the 1959 Ford Thunderbird shop manual it shows it. If you don't have the manual I can post a picture of the page, just let me know.

At any rate, my carb does not have the ball check.

So, I used a blob of grease on the body of the carb between the the body and the actuating arm of the secondaries. I left about 1/8 of an inch between the grease and the actuating arm of the secondary. Warmed up the motor and took it for a spin. I have a close ratio 4 speed. I floored it and ran it up to 4000 rpm in first, shifted to second and did the same. I pulled over to check and the grease hadn't been touched. Thus, it seems my secondaries are not opening. Tried it twice.

Any one have ideas on what to start with when the secondaries don't seem to work?

Gary, thx for the info on my manual choke. This car is sort of a "ratrod" kind of project so I will most likely use something like an old valve for the choke pull knob - it doesn't need to look original.

thx, Dave J

[davidmij]

Wait a minute, hold the press.

I just went through the the troubleshooting on page 2-18. I looked at the secondary vacuum pick up tube and it's not there. It was bent when I put it together so I bent it back. It must have kinked the tube because it's been broken off. I looked around my work table and found the piece on the floor - THANK HEAVENS. If that thing had fallen off when the carb was on it would have sucked right into the motor. It must have been barely hanging on when I bent it back and it kinked.

Luckily I have my old carb for parts, I'll replace the top plate and see if the secondaries start working.

more to come.......

[jopizz]

I see the check ball on page 2-25 as you indicated but it's not shown on the exploded parts view on page 2-27. Strange. I've taken dozens apart and have never seen one installed. There are quite a few typos in the manuals so I wouldn't take it as gospel.

John

[davidmij]

There's a great video on www.youtube.com done by "Mikes Carburetors" and it's free. I used two of them to do my carb. He shows a primary pump check ball too. He say's some have them, some don't. It's at 23:20 into the video if you want to check it out.

https://www.youtube.com/watch?v=BUrP_kTbMXs

He also has a couple of shorter videos on how to check the 4100 for operation. Be sure to check it out.

So, I changed out the top plate on my carb and YEEHAW, the secondaries open. I floored it in 1st gear and right about 3500 rpm I could feel them kick in. I pulled over and checked the grease blob trick and sure enough there was grease on the actuator arm.

Another thing I notice is it really pops and growls when I down shift - you know the sound, like little backfires. Is that probably caused by running too rich, or could it just be because of the little glass pack mufflers?

Hopefully tomorrow I will get warmer weather and I can go through adjustments and timing for a good hour and get it just right.

thx again, Dave J

[KULTULZ]

So, I changed out the top plate on my carb and YEEHAW, the secondaries open. I floored it in 1st gear and right about 3500 rpm I could feel them kick in. I pulled over and checked the grease blob trick and sure enough there was grease on the actuator arm.

Another thing I notice is it really pops and growls when I down shift - you know the sound, like little backfires. Is that probably caused by running too rich, or could it just be because of the little glass pack mufflers?

Hopefully tomorrow I will get warmer weather and I can go through adjustments and timing for a good hour and get it just right.

thx again, Dave J

It is normal for it to pop when gearing down (no fuel pressure applied) as the mixture is overly rich and is being fired late and maybe entering the exhaust system. Remember the NASCAR cars when backing out of the throttle and flames being shot?

It may be overly rich and the mufflers don't help much either... Have you done a spark plug reading?

As for the secondary check ball, it may not have been used on all models. You need the CARB I.D. NO and cross it to the MPC under Basic PN 9576. I would imagine most fall out at dis-assembly unnoticed.

[YellowRose]

4100 autolite help

Thanks to the posting by David ~ davidmij on the Autolite 4100 video by Mike's Carburetors, there are now 6 of his videos posted in the Technical Resource Library (TRL). Including the one on how to download the Autolite 4100 4 Barrel Carburetor Manual. Check them out in the Carburetor section. The TRL link is always part of my signature element. Just click on the link! Thanks, David!

[davidmij]

No problem Ray, thx for organizing it, and making it easy to get to. I just saved that manual, it will come in handy.

Gary, it also pops just a little while idling once it's warmed up. Is that normal, or should I work on adjusting the mixture a little more lean?

Dave J

[KULTULZ]

Gary, it also pops just a little while idling once it's warmed up. Is that normal, or should I work on adjusting the mixture a little more lean?

Dave J

I'm sorry Dave, I did not notice your post.

The occasional misfire may be due to the mechanical choke (your fully opening it too soon). Apply it very lightly during cold idle and see if the idle improves. The choke has to maintain a rich mixture until the heat riser feature takes over. A properly adjusted auto choke does this automatically.

I am also sending Ray a photo (within Shop Manual) showing secondary check valve (ball).

...mmm...

Let me try it this way-

http://www.tocmp.com/manuals/Ford/1958/Service/index.html

Go To Page 2-61

[davidmij]

Funny that you just posted this Gary. Just yesterday I went through the adjustments again. I didn't have a tachometer before and I realized I hadn't set the timing since installing it. I got the car good and warm, adjusted my idle to just above 600 rpm and reset the timing to about 8 or 9 degrees. (It was around 6 before) I them reconnected the vacuum advance line and adjusted the jets. Took it for a spin and it did much better. Still pops and growls when down shifting, especially when rolling down hill, but not so much while idling.

I'll tweak the jets some more today and see if I can get it even better. The choke seems pretty good now.

My carb is supposedly from a 68, and the old one was from a 67 LTD. I'm guessing the check ball, (and a few other things) changed over the years.

regards, Dave J