1949 F-1 carb linkage trouble

[Steve S.]

I am working on a 1949 F-1 V-8. It was restored about 30 years ago and used very lightly since. As far as I can tell it has been kept pretty much the way it was built. It has some issues that need to be sorted out, but it runs and drives pretty good. The most serious drivability issue it has is one I hope you can help me with.
When you push on the gas pedal there is a resistance, with no RPM gain, and then no resistance with a lot of RPM gain, leading to some very jerky starts and less than smooth shifts. I believe that the problem stems from the position of the arm on the throttle shaft that has the ball end on it. The throttle linkage from the firewall to the carburetor is trying to pull the ball straight back coming off idle.(instead of in an arc) This causes the two spring loaded ends of the throttle rod to stretch out, and after forcing the throttle shaft to rotate clockwise a degree or two, the springs return, and the throttle moves just the way it should. It appears that the arm on the carb with the ball on it may have been loose at one time, as it looks like someone may have peened it back in place. So my first question is does the throttle arm on this carb look like it is in the correct position? Thank for your help.

[cmbrucew]

Steve S
Look at the next post, 53 mercamatic for a picture of throttle linkage.


Bruce

[petehoovie]

Originally Posted by Steve S.

So my first question is does the throttle arm on this carb look like it is in the correct position? Thank for your help.

[Bob C]

Here's a couple of pictures to compare to yours.

[Ross F-1]

I don't think that is a stock truck carb. Is there another hole that the ball at the carb end could be placed in? You seem to be right that it is trying to pull at the wrong angle, because the ball is too far forward and too high.

[Terry,OH]

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When you remove the throttle linkage from the Carb. How does the hand operation of the Carb throttle feel ?

[Steve S.]

Thank you all for the replies. CM Bruce, I can't locate the post you refer to, but the linkage in Bob C's picture of the red engine especially looks like the ball is lower than mine. Ross, there is no other hole for the ball connection to go in. How can I tell if the carb is the right one for a truck? It has a bit of throttle shaft sticking out of the driver side, maybe for a hand throttle, does that help to ID it?Terry, the throttle works just fine by hand with the throttle rod disconnected. I guess I need to find another throttle shaft, or a different carburetor. I didn't want to go changing things without some idea that my theory was correct. Thanks again

[alanwoodieman]

change out the return spring! it should be on the throttle rod on the firewall

[tubman]

Originally Posted by alanwoodieman

change out the return spring! it should be on the throttle rod on the firewall

The problem is, that the original spring breaks once in a while. They are almost impossible to replace without removing the engine, so a lot of times, people add a "helper". If this is not the case here, by all means remove the "helper", Unfortunately, that's usually not the case

[1952henry]

That is most definitely not the correct “crank” on throttle shaft. I THINK that is for an automatic equipped car, or perhaps a later y-block

[1952henry]

IMG_0397.jpeg

The crank or arm should resemble this.

[1948F-1Pickup]

This is what it looks like on my '48.

[petehoovie]

Originally Posted by 1948F-1Pickup

This is what it looks like on my '48.

[1952henry]

That^^^^ looks right.

[Ross F-1]

Originally Posted by alanwoodieman

change out the return spring! it should be on the throttle rod on the firewall

The spring is attached to the linkage correctly for a truck; but the carb end should go to a hole in the plate with the choke cable clamp.

[petehoovie]

Originally Posted by Ross F-1

The spring is attached to the linkage correctly for a truck; but the carb end should go to a hole in the plate with the choke cable clamp.

[52flthed]

The throttle return spring should be attached to a ‘Y’shaped bracket on the back of the carburetor. Your spring isn’t attached correctly and might not be the correct spring.

[52flthed]

Here’s some photos

[Steve S.]

Just to follow up, here is a report: I purchased an old stock re-manufactured carburetor 8RT-9510-A. It seems to be a perfect replacement. The throttle linkage attaching point is just a few degrees more clockwise than the one that came on the truck. I installed the carb, and the throttle operation is as smooth as could be. Right out of the box, the truck idled slow and smooth. I sorted out some ignition problems, and the truck runs beautifully. It is a pleasure to drive now. The attached picture shows the old carb on the left, and the replacement on the right.
I still need to get the throttle spring corrected, but thanks to your help, I know where it needs to be. Again, thanks to all. Steve.