Running rich

[ggenovez]

Hi all,

I had a problem with fuel supply that I recently resolved. Now I can get her to start and she'll rev high ~2000 RPM and slowly go down and stall. Checking the plugs I see black suit build up. I cleaned up the plugs and it's still doing it.

Any advice?

Thank you in advance.

[ggenovez]

Anybody?

She still won't idle. as soon as I let go of the throttle, she stalls.

[pedrocamp]

Need more info to help you... Zenith carbs correct? What did you solve? A few things that may be causing the rich condition... Float levels? Fuel pressure? Jets correct? Choke setting?

[mosu]

I'd start with the float level - make sure it's within spec. I used this reference:

Mercedes Benz Zenith Carb Manual | JaimeKop.com

Open up the carbs and make sure that the passageways and jets are clean, the throttles close and the float valve is working smoothly. Set the choke and fast idle on the front carburetor to spec and install.

If you have no vacuum leaks, it should start and run ok. Have you run through these checks?

[ggenovez]

Yes, I have zethins. The probem was I would not get fuel but I would get pressure from the new pump. Replaced the fuel lines.

I have checked the floats. They're within specs. Pressure is correct. 3-4 PSI

Carbs were disassembled, cleaned, air passed through all the openings. I'll go through the manual and check everything else. Any ideas would be greatly appreciated.

[mosu]

Have you tried isolating the fault by routing the fuel pump inlet into a Jerry can of gas? That will isolate any blockage on the lines and tank.

[janikphoto]

Originally Posted by ggenovez

...Checking the plugs I see black suit build up...

That'll definitely cause problems, if you are having black suits clog the engine!!! I hope it's a cotton and wool blend, as rayon will melt in the combustion chamber! Just joking with you, I know you meant soot. I'd say it sounds like something is sticking or clogged. You might need to redo that carb rebuild.