I have a 78 20R pickup, with a 23/36 Webber, with the electric choke. I need to replace some of the gaskets cause its leaking. Before I tare into it and rip it apart. Im asking from some of you guys that are familiar with these carbs. To help me figure out some problems I'm also having besides the leaking gaskets.

1. It starts really hard when its hot. If I drive it to the store a few miles away. Trying to restart it at the store I have to floor the gas in order for the truck to start. Otherwise the starter will just turn the truck over and over for ever.
2. Applying the breaks, the truck wants to stall. Happens only when its hot.
3. When turning off the engine the engine backfires. Shakes violently then stops. This also happens mostly when its hot.

Any help on this or ideas on how to tackle these issues are greatly appreciated.

 

-**check back tomorrow evening, husband has this truck but is asleep, I'll put him on it tomorrow!!!**(yup, wifey scrolls yota forums at night not FB I am addicted to my 89 Toyota pickup as well &#128514

 

Working through it as well brother

 

Lets bounce ideas off each other 2 brains are better then one. Let me know where you at and I will do the same. I'm planning on tarring into the carb this weekend.

 

First thing that comes to mind on the hot start problem is possibly flooding . Generally with carbs that are flooding, you hold the throttle open to allow full air flow to clear the flooding. It could be caused by improper (too high)float in the carb. Another possibility is percolation due to heat if you do not have the appropriate base gasket or spacers in place. You should just try to get a rebuild kit for it and follow the instructions.

Another thought is fuel pressure. Are you running an electric or mechanical pump? Is the pressure correct for this carb?

 

Those are two good points about flooding. I do have to floor the gas peddle to start it. The longer I wait between running and re-starting the better it starts, maybe also cause the truck cools down. I have the kit and Im going to tear into it this weekend. As far as spacer go I do have one but the instructions do not mention anything about that for this truck. Im running an electric fuel pump, I also have a fuel pressure regulator installed, running 3bar, Which is the recommended pressure for this carb. Once I open the carb this weekend im going to take tons of pics, I don't know what Im going to find the carb is 6 years old, some gaskets are leaking there is a stain on the intake manifold form the gas leak. As you can see in these pics.

 

3bar??? That's near 45 psi
Don't you mean 3 pounds per square inch????

 

The fuel pump identifies as a GT3 RS. Living its best life.

You are correct. I did mean to say 3lbs. My mistake. Thank you for the correction.

 

So I was some what successful today. Tore into the carburetor today. Did not see anything that was out of the ordinary. The float had a lot of play the needle and seat position. Other then that the carb looked in good order not a lot carbon build up. The only thing that raised questions was the back splash on the top of the carburetor cover.

Oil and gas mixture sprayed on the top. This is odd to me.

I was able to change the gasket on the accelerator pump diaphragm, this was leaking. I did notice some dirt and corrosion on the inside. Clean it up before re-installing.

I was not able to change the other piece that was leaking. On the secondary shaft there is a shaft retaining bushing. That was not part of the rebuild kit, actually the kit is quite light on parts and the paper gaskets do not match the well on the carb, very disappointing. I just tightened the fixing nut really tight. Here is a picture of the actual secondary shaft retaining bushing. This was leaking really bad, I dont think tightening the fixing nut would fix the problem. I will keep on eye on it for the next few days see what happens.

This is how far I got so far. Still dont know why it starts hard when hot, and why it wants stall when applying the breaks.