Griff

I doubt it needs rebuilt from what you have posted. Just try a 50cc accelerator pump available at most automotive stores. Then play with a 1/8-1/4 turns of the 4 corner idle.

ptlmveng

That'll be a cheap and easy fix if it works. Should I adjust the idle mixtures in or out 1/8-1/4? Does the carb have to come off the intake to change the accel pump?

Griff

Carb has to come off to get to the screws that hold the acc pump on. Start by turning them out to richen it a little.

ptlmveng

I did not change the accel. pumps, but I did adjust the 4 corner screws. I found that the best was about 1/4 turn in from the 1.5 out from seated was the best. idles smooth at 950 rpms. I can't get the idle down any farther that that. Wish I could but I tried everything and can get it to drop. The two round plates that open when throttle is applies are completely closed. I can here them closing before the linkage is hitting the idle adjust screw. Any suggestions?

Just want to say thanks for all the advice so far. Its been extremely helpful in resolving my problems.

satisfactionII

I think your idle is too fast, somewhere around 600 rpm at idle is best. The throttle plates aren't supposed to control the idle speed, the idle circuit controls in the carb controls the idle speed. I think you may have adjusted it out to far to get the low rpm idle. Maybe that is what it takes to idle smoothly on your carb and engine?

I'm no expert, just my opinion.

ptlmveng

If I do turn the screws further in it lowers the rpm, but most of what I've read has been start with screws 1.5 out from seated. If I go in any further , I guess that would make it very lean. Lean at idle, is that not ok?