Need carb help!

[BunnySlippers]

I have a stock 78 B210. I have never been a carb guy, always had FI in my cars until now.

I need some help setting my carb to run properly. I thought I had it pretty decent a while ago, but now it wont idle.

Does anyone know how many turns in or out all the adjusters should be at?

[datzenmike]

Be sure valve lash has been checked and adjusted to spec with hot motor.

 

Be sure the timing is set

 

 

Turn the idle screw in to increase the speed so it will keep running, not too fast. turn the idle mixture screw in and out to get the best smooth/fast idle. Turn idle speed down. Adjust mixture for fastest smooth idle. turn idle speed down.... repeat until you cannot improve idle quality.

[ericsb210]

Also, Carbs just don't start idling poorly on the norm. Something has caused an imbalance in the air/fuel or spark mixture (or compression). Most times it would be a fault of vacuum. Check all of your vacuum lines and the manifold at carb and head for any leaks, best way is with a can of wd40 or the like and listen for any changes in rpm or steadiness of engine. Take your time doing it, give each component time to respond before moving on.

 

Next would be fuel or in this case the idling circuit of the carb. Obstruct the air supply from the top of the carb momentarily to see if you may dislodge any foreign objects that have lodged in the circuit. On that model I believe you have two fuel filters, one on the passenger side of the firewall and the other at the inlet of the carb. this one can be hard to access. make sure both are clean.

 

At this point check your spark plugs for even fire. And check as stated in previous post.

 

If none of the above work, check for compression. If all good, then rebuild the carb. This is not an easy task, if your not familiar with carbs try to find an old school mechanic in your area.

[BunnySlippers]

Posted that in a hurry yesterday. More info now.

I rebuilt the carb several months ago, and it took a while to get the electronic choke set right. I had it set properly in the AZ summer. I just replaced the choke pull off, and it's colder now. So it wasnt starting right away and the idle was finicky. So I started trying to adjust it and it went all wrong.

I also did a big tune up on the engine a month or so ago. Adjusted valves, checked compression, new ignition pick up, wires, plugs, cap, rotor, air filter, adjusted timing, and an oil change.

I think I just need someone to help me out with manning the ignition so I can adjust the carb. Getting it started and then trying to make it run long enough for me to run around to the adjusters was frustrating to say the least last night. Guess it's time to enlist the girlfriends help.

 

DatzenMike, thanks for the advice, I'll hopefully have time on sunday to work on it again. I'll let you kniow how it goes.

[Nicholas7620]

You may have developed a sudden vacuum leak.