Odd about these carburetors!

[spidernut]

Step 1: Carb is acting up
Step 2: Rebuild carb
Step 3: Carb is still acting up worse than before
Step 4: Take carb apart and find broken casting, hmmmm, how did that happen?
Step 5: Rebuild another carb and install
Step 6: Other carb is acting up in a different way, but getting much better gas mileage. Won't idle intermittently, find problem with idle stop solenoid, back out 1/4 turn and seems to run great, then has intermittent problem with idling.
Step 7: Check function of idle stop solenoid ... everything O.K.
Step 8: Disassemble carb to ensure rebuild was correct. It was O.K., reinstall, still doesn't work right. hmmmmm. Seems like accelerator pump is not working
Step 9: Tweak carb, check vacuum lines, verify everything works, adjust fuel mixture, still doesn't work right. Verified accelerator pump is working right. hmmmm
Step 10: Remove carb, take good parts from one carb, rebuild original carb, still doesn't work right. Still has major hesitation when initially accelerating. hmmmm. Fuel mixture goes from lean to rich in about 1/2 turn of the fuel mixture screw.
Step 11: Look down carb to see what's going on. Find out accelerator pump flow is flooding the engine causing the brief hesitation. Can't make sense of that, but decide to tighten idle stop solenoid a bit more on this carb out of curiosity (remember, I had to loosen it on the other carb). Hesitation is significantly better and now adjusting the fuel mixture takes 1 1/2 turns. Tighten it even more and it works even better. Tighten it even more (about as far as it can possibly go) and all carb problems are solved.

Lesson learned: check how far the idle stop solenoid is threaded into the carb before wasting time on steps one through ten.

So, I drove the car to work and back (almost 50 miles) and it ran fantastic..in fact, never better. I'll find out soon enough, but it seems to have increased fuel mileage significantly as well. I love it when things work out but why couldn't I find this in step one instead of having to go through several weeks worth of brain racking torture?

[vandor]

I assumed the idle solenoid has the be threaded in until tight. Why would you not thread it in all the way?

[spidernut]

When it was threaded in fully on the replacement carb that I rebuilt, it would not idle at all. The RPMs had to be at about 1500 to keep it running. When I backed it out very slightly, it idled fine but had some intermittent issues. Go figure!

When I rebuilt the original carb from the car and put it back on, I had tightened it down fully with a new O ring. It wouldn't idle smoothly so I tightened it up even more and it ran better, then even more until it was pretty darn tight and it now runs great. My best guess is that the new O ring had caused it not to seat into the carb far enough.

I'm just thrilled that I've now put about 100 miles on the newly rebuilt carb and it is running fantastic, idling better than ever and the gas mileage seems much better.