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Old 09-21-2022, 09:33 AM   #1
Bunky
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Question monojet ?

So I have a 74 250 6 cylinder in my C15.the thing would barely run when I got it did compression check (130-150 psi ). Rebuilt the carb, fuel filters, complete tune up plugs ,wires, cap & rotor, points and condenser.etc. checked for vacuum leaks etc. Still have a hesitation if you try to take off or rev it sitting in the drive.

It idles with the idle stop screw backed all the way out,. But the idle mixture screw is out more than I feel it should be probably 4 turns.

Anyone have any suggestions?

Also looking for the thread size of the idle solenoid as I would like to replace it with a bolt.or screw.
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Old 09-21-2022, 06:14 PM   #2
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Re: monojet ?

Turn the mix screw in a bit at a time until it stumbles.
What did you set the initial timing at?
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Old 09-21-2022, 07:08 PM   #3
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Re: monojet ?

Quote:
Originally Posted by geezer#99 View Post
Turn the mix screw in a bit at a time until it stumbles.
What did you set the initial timing at?
I have tried the timing at all way to 12 degrees..
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Old 09-21-2022, 08:06 PM   #4
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Re: monojet ?

How much vacuum do you have at idle?
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Old 09-21-2022, 08:19 PM   #5
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Re: monojet ?

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How much vacuum do you have at idle?
18-20 in
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Old 09-21-2022, 09:58 PM   #6
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Re: monojet ?

Do you have an idle tach? The vacuum seems good.

Does the monojet have an acceleration pump or equivalent? Hesitation on acceleration is often an issue with not enough extra gas being added as the throttles are opened.
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Old 09-21-2022, 09:58 PM   #7
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Re: monojet ?

Could be flooding a bit or have a dripping booster.
Look in the carb while idling. Look for any excess fuel. Should be none.
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Old 09-21-2022, 10:52 PM   #8
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Re: monojet ?

If it has sat a bunch I am betting on an a bad accelerator pump.
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Old 09-22-2022, 06:01 AM   #9
Bunky
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Re: monojet ?

Quote:
Originally Posted by Dead Parrot View Post
Do you have an idle tach? The vacuum seems good.

Does the monojet have an acceleration pump or equivalent? Hesitation on acceleration is often an issue with not enough extra gas being added as the throttles are opened.
Yes I do happen to have a hand tach and it idles about 600 with the idle stop solenoid all the way out and the idles screw where I mentioned above at about 4 turns out ..

I'm going to try screwing in the solenoid and trying to adjust the idle again see if maybe there's something with that.
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Old 09-22-2022, 06:02 AM   #10
Bunky
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Re: monojet ?

Quote:
Originally Posted by geezer#99 View Post
Could be flooding a bit or have a dripping booster.
Look in the carb while idling. Look for any excess fuel. Should be none.
I will check this tonight and see. When shut off it appears to have a good squirt and no hesitation when pumping..
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Old 09-22-2022, 06:03 AM   #11
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Re: monojet ?

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Originally Posted by burnin oil View Post
If it has sat a bunch I am betting on an a bad accelerator pump.
Carb was just rebuilt, new accelerator pump.
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Old 09-22-2022, 08:41 AM   #12
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Re: monojet ?

How extensive was the carb rebuild?
Did you tear it apart completely or just a cleaning and gaskets and float adjustment?
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Old 09-22-2022, 08:49 AM   #13
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Re: monojet ?

I tore it down soaked it and installed a rebuild kit..

This is what it looked like when I opened it up.
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Old 09-22-2022, 09:15 AM   #14
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Re: monojet ?

Did you remove the throttle plate and check the throttle shaft?
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Old 09-22-2022, 09:16 AM   #15
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Re: monojet ?

Yes soaked that's as well.
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Old 09-22-2022, 09:38 AM   #16
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Re: monojet ?

Just so’s we’re on the same page!
You did remove the throttle plate and remove the throttle shaft from the carb.
Is that correct?
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Old 09-22-2022, 09:42 AM   #17
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Re: monojet ?

Quote:
Originally Posted by geezer#99 View Post
Just sos were on the same page!
You did remove the throttle plate and remove the throttle shaft from the carb.
Is that correct?
No I didn't pull the shaft from the throttle plate. Just soaked and cleaned the assembly together after removing it from the carburetor bowl.
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Old 09-22-2022, 09:50 AM   #18
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Re: monojet ?

Good.
Have you checked the vac pot on the distributor is good?
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Old 09-22-2022, 09:56 AM   #19
Bunky
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Re: monojet ?

Quote:
Originally Posted by geezer#99 View Post
Good.
Have you checked the vac pot on the distributor is good?
It seems to move when I rev the engine or when I in plug and plug the vacuum..

I think I need to pull the carb back apart and re clean it.
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Old 09-22-2022, 01:55 PM   #20
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Re: monojet ?

Be sure the float level & metering rod are adjusted to specs.
With the engine off, look down the throat of the carb & open the throttle. You should see a stream of gas going into the throat.

George
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Old 09-22-2022, 01:59 PM   #21
Bunky
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Re: monojet ?

Quote:
Originally Posted by Wrenchbender Ret View Post
Be sure the float level & metering rod are adjusted to specs.
With the engine off, look down the throat of the carb & open the throttle. You should see a stream of gas going into the throat.

George
I did this the other day and it appears to be spraying and no hesitation in the spray as soon as I move the throttle it's spraying.
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Old 09-22-2022, 08:04 PM   #22
Bunky
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Re: monojet ?

Ok so tonight I went out and rechecked some things, sped the idle up a little and readjusted the carb was a little better..

So then I was checking again for vacuum leaks and noticed the dash pot isn't holding, so I plugged that line off.

I also had my vacuum advance hooked to full vacuum at idle.. changed that to ported.

Seems better but probably should re adjust the carb again since I changed the advance on the timing.

My other question is if I do have the metering rod too low would this affect the take off hesitation?
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Old 09-22-2022, 11:23 PM   #23
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Re: monojet ?

[QUOTe

My other question is if I do have the metering rod too low would this affect the take off hesitation?[/QUOTE]

Definitely. You may have to readjust the idle speed when you changed from full vacuum to ported.
Make Shure the gasket between the throttle body & float bowl is the correct one & installed correctly. 2 gaskets come with the kit & it is easy to install it wrong.
George
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Old 09-22-2022, 11:50 PM   #24
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Re: monojet ?

Quote:
Originally Posted by Bunky View Post

So then I was checking again for vacuum leaks and noticed the dash pot isn't holding, so I plugged that line off.
Dash pot!
What dash pot?
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Old 09-23-2022, 05:03 AM   #25
Bunky
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Re: monojet ?

Quote:
Originally Posted by geezer#99 View Post
Dash pot!
What dash pot?
Choke pull off
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