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Zoom .. I figured it out!

Posted: Sat Jul 27, 2019 5:11 pm
by Mark Osterman
I finally figured out how to get this U&J to perform as expected. I tried adjusting the needle on the bottom but if I gave it too much gas the engine sputtered. If turned it the other direction the slightest there was not enough gas. The tolerance was so touchy and I couldn’t get it right no matter what I did. Don’t know if it’s the modern adaptation of the Viton needle tip or what.

I adjusted the float which helped a little. I installed 5/16” steel fuel line and didn’t see much difference. Then I wondered about a choke adjustment like the one offered by U&J and was regular equipment on an OF. I have a very nice remote choke adjuster marked gas - air and was going to install that, but before I do .. I wanted to see proof of concept. So I took a small piece of leather and wedged it into the firewall slot for the choke rod as illustrated.

Ok .. now that’s what I’m talking about. I drove a little and while cruising in high gear at around 30 mph I pulled out the choke rod slightly and got an increase in speed and smoother running. I had been having difficulty previously in getting a smooth transition and speed after 35 mph and 40 mph was really difficult to maintain before. I could never get the car to go as fast as 45 mph. Well, in my test drives I had smooth acceleration up to 45 and stopped acceleration when I got it up to just under 50 mph ... too fast for safety in my opinion. But I cracked the problem. So it’s either a needle and seat problem that needs attention or it simply needs the extra draw afforded by the slight fixed adjustment of the choke control. Guess I need to put that steering column choke control back on. I had used it last with the OF that I ran before getting the U&J.

Re: Zoom .. I figured it out!

Posted: Sat Jul 27, 2019 9:18 pm
by Mark Osterman
This is where the car ran best in high gear.

Re: Zoom .. I figured it out!

Posted: Sat Jul 27, 2019 9:41 pm
by Ruxstel24
I won't pretend to be a U&J expert, but...
If you have the choke butterfly partially closed to make it rich enough, you are also restricting airflow. If you can figure out how to richen the high speed mixture wo/the choke, it should REALLY come to life !!

Re: Zoom .. I figured it out!

Posted: Sat Jul 27, 2019 10:49 pm
by Mark Osterman
Well, that’s the dilemma. I have tried all I know to increase the fuel. I suppose there is the potential of increasing the fuel by changing the geometry of the venturi inside but I don’t know how to tweak it. The car idles beautifully and now accelerates smoothly to beyond the speeds I intend to drive. So, I guess I have circumvented the system to do what I want. Here is the Air/Gas control I can mount on the steering column to increase the fuel for higher speeds. I previously used it with an OF.