Weber help 1962 544

lelshaddai · Nov 18th, 2018, 01:24

The engine is a B20B from 69 144.

I have been having idle problems and have it now narrowed down to the weber. Timing is correct (at 14, Weber suggests a little more than book value), cap, rotor, points replaced, plugs good, wires good, fuel pump replaced. I replaced the throttle plate bushings with new ones since it had a slight vacuum leak. Now I have a new problems.

I cannot get the carb to adjust the idle below 800rpm. Flipped the throttle plates over and that made it worse.

Idle mixture screw will screw all the way in and the engine likes that better. I starts to shudder at 3/4 turn out. I know this is not correct. From what I read I should try smaller idle jets. I am using 50/55 now. It did not seem to change from when I used a 60/55 and 55/55 combinations with no effect. The idle screws all the way in and the engine still runs OK, Checking I did not find any vacuum leaks. The port on the carb is plugged. Carb cleaner sprayed around the carb has no effect. Carb cleaner sprayed around manifold and valve cover has no effect.

I rebuilt the carb with new parts.
Would dropping to a 40/45 jet work?

I have posted similar things before. I just do not want to spend lots of time on something minor like the jets.

arcturus · Nov 18th, 2018, 09:02

Scrap it and get some SU's.

old fart · Nov 18th, 2018, 14:19

I have the same carb on my 544, and that won't idle below 800, but so what?
That's low enough, and it goes like stink and is good on fuel, so I'm happy like that.

lelshaddai · Nov 18th, 2018, 14:50

I understand that the 800rpm idle is OK, and yes it moves very well. I would like to get the jetting correct since the idle mix screw goes all the way in.

tdz840 · Nov 18th, 2018, 20:06

Clean the plugs (brass brush), run the engine for ten minutes and check the plugs. Just confirms you may be running rich
Have you checked the throttle plate is completely closed ensuring the throttle cable(or rod) is playing no part in the idle setting?. By that i mean disconnecting the throttle, ensure the throttles are completely on the stops. Then wind the idle screw (NOT idle jet) in 1.5 turns and set the throttle cable (or rod) to that setting.
This ensures you are fueling only from the idle jet and havent uncovered the progression holes or the mains (unlikely).
That size idle jet is small for your engine so i think you are fueling from another source.
If you have wound the idle jet in fully i suggest you are running rich, again pointing potentially to the progression holes (or choke - is it fully off?) being uncovered.
Potentially, have you thought about knocking the timing back a couple of degrees?
I agree though, the SUs are a better bet.

lelshaddai · Nov 19th, 2018, 01:35

OK, so I have a 60/55 jet combo now. Loosened linkage to make sure it does not interfere with idle. Changed timing to 12 degrees. Idle mixture is at 3/4 turn now. No conflict with choke. Idle is at 825rpm. Runs smoother, still shakes/shimmy once in a while. However takes off really well. Great acceleration. May have to call it good for now until I can test it more. Still no vacuum leaks detected after replacing throttle plate bearings/seals.

Nov 18th, 2018, 01:24	#1
lelshaddai Senior Member Last Online: Dec 30th, 2022 02:42 Join Date: Jun 2015 Location: Mesa, Arizona	Weber help 1962 544 The engine is a B20B from 69 144. I have been having idle problems and have it now narrowed down to the weber. Timing is correct (at 14, Weber suggests a little more than book value), cap, rotor, points replaced, plugs good, wires good, fuel pump replaced. I replaced the throttle plate bushings with new ones since it had a slight vacuum leak. Now I have a new problems. I cannot get the carb to adjust the idle below 800rpm. Flipped the throttle plates over and that made it worse. Idle mixture screw will screw all the way in and the engine likes that better. I starts to shudder at 3/4 turn out. I know this is not correct. From what I read I should try smaller idle jets. I am using 50/55 now. It did not seem to change from when I used a 60/55 and 55/55 combinations with no effect. The idle screws all the way in and the engine still runs OK, Checking I did not find any vacuum leaks. The port on the carb is plugged. Carb cleaner sprayed around the carb has no effect. Carb cleaner sprayed around manifold and valve cover has no effect. I rebuilt the carb with new parts. Would dropping to a 40/45 jet work? I have posted similar things before. I just do not want to spend lots of time on something minor like the jets. __________________ 1962 Volvo PV544 1951 Studebaker Starlight State Commander Coupe 1953 Studebaker Starlight Commander

Nov 18th, 2018, 09:02	#2
arcturus arcturus Last Online: Today 08:12 Join Date: Mar 2006 Location: Sagres Portugal	Scrap it and get some SU's. __________________ life's too short to drink bad wine

Nov 18th, 2018, 14:50	#4
lelshaddai Senior Member Last Online: Dec 30th, 2022 02:42 Join Date: Jun 2015 Location: Mesa, Arizona	I understand that the 800rpm idle is OK, and yes it moves very well. I would like to get the jetting correct since the idle mix screw goes all the way in. __________________ 1962 Volvo PV544 1951 Studebaker Starlight State Commander Coupe 1953 Studebaker Starlight Commander

Nov 19th, 2018, 01:35	#6
lelshaddai Senior Member Last Online: Dec 30th, 2022 02:42 Join Date: Jun 2015 Location: Mesa, Arizona	OK, so I have a 60/55 jet combo now. Loosened linkage to make sure it does not interfere with idle. Changed timing to 12 degrees. Idle mixture is at 3/4 turn now. No conflict with choke. Idle is at 825rpm. Runs smoother, still shakes/shimmy once in a while. However takes off really well. Great acceleration. May have to call it good for now until I can test it more. Still no vacuum leaks detected after replacing throttle plate bearings/seals. __________________ 1962 Volvo PV544 1951 Studebaker Starlight State Commander Coupe 1953 Studebaker Starlight Commander

Nov 18th, 2018, 14:19	#3
old fart Master Member Last Online: Mar 28th, 2024 14:15 Join Date: Apr 2012 Location: Droitwich	I have the same carb on my 544, and that won't idle below 800, but so what? That's low enough, and it goes like stink and is good on fuel, so I'm happy like that.

Nov 18th, 2018, 20:06	#5
tdz840 VOC Member Last Online: Dec 14th, 2023 11:57 Join Date: Nov 2004 Location: fareham	Clean the plugs (brass brush), run the engine for ten minutes and check the plugs. Just confirms you may be running rich Have you checked the throttle plate is completely closed ensuring the throttle cable(or rod) is playing no part in the idle setting?. By that i mean disconnecting the throttle, ensure the throttles are completely on the stops. Then wind the idle screw (NOT idle jet) in 1.5 turns and set the throttle cable (or rod) to that setting. This ensures you are fueling only from the idle jet and havent uncovered the progression holes or the mains (unlikely). That size idle jet is small for your engine so i think you are fueling from another source. If you have wound the idle jet in fully i suggest you are running rich, again pointing potentially to the progression holes (or choke - is it fully off?) being uncovered. Potentially, have you thought about knocking the timing back a couple of degrees? I agree though, the SUs are a better bet.

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