Slant Six Forum
https://www.slantsix.org/forum/

funky holley 1920 idling rough
https://www.slantsix.org/forum/viewtopic.php?t=53563
Page 1 of 1

Author:  Brothercactus [ Thu Oct 10, 2013 3:34 pm ]
Post subject:  funky holley 1920 idling rough

Heya!

I recently scored a gunky ol 1920 to replace the one i have. The carb ive been using is pretty worn through the throttle shaft.

I cleaned the new one up and rebuilt it. Now its on the car but i cant get it to idle very smooth. It seems to idle best with the idle mixture screw all the way in. The further i let the mixture screw out, the chunker the idle gets. The mixture screw doesnt appear to be influencing the idle much. The closer to all the way in the screw is, the car runs a little smoother, but not by much.

The float is set correctly i think. Even so, it ran the same way when i originaly put the carb on and the fuel level was low.

The float bowl also leeks a bit of gas after i drive it and the car sits over night.

When driving, the car seems to run pretty good. Better than the old carb for sure. Doesnt idle as smooth though. The valves probably need some lovein, but not this bad.

Thank you! Im learning so i could easily be missing something.
Car is 67 Valiant 100.

Author:  carlherrnstein [ Fri Oct 11, 2013 6:21 am ]
Post subject: 

If it idled good before the carb swap I would guess that its not the valve adjustment.

I wonder if someone at some point put the super torque to the idle adjusting screw and ruined the area where the needle seats?

Author:  pishta [ Fri Oct 11, 2013 1:38 pm ]
Post subject: 

How did you clean the power valve body? Trying to think what the rule was for idle screw behavior, ie no effect means your jets are too big or something. No vacuum leaks, eh?

Author:  Brothercactus [ Sun Oct 13, 2013 11:27 am ]
Post subject: 

I am thinking that the jet might be too big. It was kind of an inspiration! Ha! Nah, i understand the carb in a new and vague way. If i sit and concentrate on everything ive read i can understand, but then it falls apart.

Anyway, are the jets interchangable? I have my other carb i can grab the jet off of.
Why would somebody put a huge jet on there? Different application?

I dont think i have any major vaccum leaks, but im looking for em.
Also maybe a worn mixture screw and seat.

Author:  Aggressive Ted [ Sun Oct 13, 2013 1:54 pm ]
Post subject: 

Quote:
Anyway, are the jets interchangable?


Yes, I have run a #56 on up to a #64. A #57 is my favorite on a stock motor. On a heavy car some folks like a #58 up to a #60.
Quote:
Why would somebody put a huge jet on there?
I have run up to a #66 drag racing to get into the 17 second range.
Quote:
Also maybe a worn mixture screw and seat.
You could try swapping idle mixture screws. Clean it up first with a red scotch brite pad.

Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/