engine

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Re: engine

Unread post by Surveyor » February 2nd, 2021, 12:28 pm

1960 M151 Run #1
"There is one nut on a M151 that is very difficult to remove....." - K8icu
"She ain't a Cadillac and she ain't a Rolls, But there ain't nothin' wrong with the radio" - Aaron Tippin
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Horst
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Re: engine

Unread post by Horst » February 2nd, 2021, 12:36 pm

Surveyor wrote:
February 2nd, 2021, 12:28 pm
This may be helpful... https://archive.org/details/PAM750-33
well, not really (or at least only partially) as it does not cover the 60amps alternator
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

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Re: engine

Unread post by Surveyor » February 2nd, 2021, 1:13 pm

Horst wrote:
February 2nd, 2021, 12:36 pm
well, not really (or at least only partially) as it does not cover the 60amps alternator
Chapter 4 or I'm imagining things.
1960 M151 Run #1
"There is one nut on a M151 that is very difficult to remove....." - K8icu
"She ain't a Cadillac and she ain't a Rolls, But there ain't nothin' wrong with the radio" - Aaron Tippin
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Horst
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Re: engine

Unread post by Horst » February 2nd, 2021, 1:18 pm

Surveyor wrote:
February 2nd, 2021, 1:13 pm
Horst wrote:
February 2nd, 2021, 12:36 pm
well, not really (or at least only partially) as it does not cover the 60amps alternator
Chapter 4 or I'm imagining things.
stupid me, sorry, you are 100% correct
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

rupert's
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Re: engine

Unread post by rupert's » February 2nd, 2021, 6:11 pm

rickf wrote:
February 1st, 2021, 8:45 pm
There is a drain on the bottom of the carb, it is a plug, not a screw. The screw is the emulsion jet. The cover on the side is the accelerator pump and as long as it is working you want to leave that alone. There are two adjustments you can make on that carb, idle speed and idle mixture. Idle speed screw is on the linkage and moves with the throttle. Idle mixture is in the mounting flange where the carb mounts to the intake manifold. You need to use the idle speed screw to bring the idle speed down to a normal slow idle speed and then you screw the mixture screw in until the motor stumbles and bit and then slowly out until it stumbles a bit and then go halfway between those two points. You should have a nice smooth idle at this point. If you have the internal mixture screw where you need a very small screwdriver to do the adjustment then yes, it can change while driving but this usually takes many miles. the way to stop it from moving is to steal your wifes very expensive fingernail polish and put a drop in there on the screw. Just a small drop and that will lock the threads from moving on there own but you will still be able to move it if you have to. And no, it does not have to be the expensive stuff. :roll: :lol:

If none of that works you may have a vacuum leak at the manifold but try this first.
Rikf! I just remembered! I have a bit broken the connection on the right side of the collector, I think it is ventilation for the spark distributor. Well, this connection is a bit cracked and possibly a little air enters, I had to put a new one but I forgot ...
Horst wrote:
February 2nd, 2021, 2:54 am
you can drain the carburetor bowl by screwing out the mentioned plug. You should catch the fuel to check for the amount of dirt coming out. But unless the carburetor is very dirty, it will not help much, but it also will not hurt.

You are adjusting the idle wrong, follow Rick's procedure.

The charging voltage is too high, you want the needle at the white mark in the green segment of the gauge. Too high of a voltage will hurt the batteries. To adjust, there is a potentiometer behind the hex screw at the alternator, same place where the cables are fastened. Remove the hex plug and adjust the voltage. You might want to double check with a voltmeter, typically on a 24V battery installation you have 28V charging voltage (but not more)
Understood Horst! I will do it with the voltmeter and adjust with this screw until leaving it at 28v
Surveyor wrote:
February 2nd, 2021, 12:28 pm
This may be helpful... https://archive.org/details/PAM750-33
I keep it! I didn't have it ... I hope I don't have to use it because translating it makes me lazy and many times I don't understand the translation well but it's always good to have them!
Thanks to all 3!

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Re: engine

Unread post by rickf » February 2nd, 2021, 8:50 pm

Where you are describing for the leak is not vacuum, it is atmospheric pressure so it will not affect the engine. the usual spot for a vacuum leak is between the intake manifold and the head.Get the carb adjusted as I mentioned first and then I will run you through the test for the vacuum leak.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: engine

Unread post by rupert's » February 11th, 2021, 7:27 pm

I go crazy! I can't get a steady idle

I have removed the screw from the lower part of the carburetor, the gasoline has come out a little cloudy but the needle was clean, I have reassembled it, I have adjusted the screw of the mixture as you have told me and I have made a video of the best idle that I have achieved, tomorrow I am almost certain that when the engine starts the idle will be different.Do you think this idle is okay?
Is it normal that I always shoot so much black smoke?

I am thinking of taking the carburetor to be cleaned at a workshop, do you think this could solve the problem?

https://youtu.be/su1rjCVsX6A

Un saludo

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Lou
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Re: engine

Unread post by Lou » February 11th, 2021, 7:48 pm

It is loading up, running too rich. Should be no black smoke. Are you sure your timing is ok? If that was a Holley carb I can tell you how to fix it. But Rick is the resident Zenith expert and look forward to his comments. :)
Take Care,
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Re: engine

Unread post by RAFINDER » February 12th, 2021, 7:30 am

rupert's wrote:
February 11th, 2021, 7:27 pm
I go crazy! I can't get a steady idle

I have removed the screw from the lower part of the carburetor, the gasoline has come out a little cloudy but the needle was clean, I have reassembled it, I have adjusted the screw of the mixture as you have told me and I have made a video of the best idle that I have achieved, tomorrow I am almost certain that when the engine starts the idle will be different.Do you think this idle is okay?
Is it normal that I always shoot so much black smoke?

I am thinking of taking the carburetor to be cleaned at a workshop, do you think this could solve the problem?

https://youtu.be/su1rjCVsX6A

Un saludo
Hi I think you have to adjust the mixture screw before adjusting the idle screw, black smoke indicates rich mixture. In addition to adjusting the ignition with an electroboscopic light
I'm sorry, but I use it to read and write the google translate.

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Re: engine

Unread post by rupert's » February 12th, 2021, 7:40 am

RAFINDER wrote:
February 12th, 2021, 7:30 am
rupert's wrote:
February 11th, 2021, 7:27 pm
I go crazy! I can't get a steady idle

I have removed the screw from the lower part of the carburetor, the gasoline has come out a little cloudy but the needle was clean, I have reassembled it, I have adjusted the screw of the mixture as you have told me and I have made a video of the best idle that I have achieved, tomorrow I am almost certain that when the engine starts the idle will be different.Do you think this idle is okay?
Is it normal that I always shoot so much black smoke?

I am thinking of taking the carburetor to be cleaned at a workshop, do you think this could solve the problem?

https://youtu.be/su1rjCVsX6A

Un saludo
Hi I think you have to adjust the mixture screw before adjusting the idle screw, black smoke indicates rich mixture. In addition to adjusting the ignition with an electroboscopic light
Rafinder, the mixing screw is adjusted between too tight and too little, in the middle, also it is where it seems to have the best idle.
For a less rich mix ... Do I have to tighten the screw or loosen it?

a greeting

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Re: engine

Unread post by rickf » February 12th, 2021, 9:26 am

Tighten it but if that screw was ever run in and tightened hard against the orifice then you will never really be able to properly adjust it. You should have a range from to lean to too rich and that should be at least a full turn of the screw. You mentioned the gas was cloudy and that is a problem. Gasoline should be clean and clear with some yellowish color to it. I don't know exactly what color yours will be over there but it is surely not cloudy. That is a sign of old or contaminated gas. That could be part of your problem. How old is the gas?

I just watched the video and it is running way to fast and way to rich. You did turn the idle down some and now you need to turn the mixture screw in until it smooths out and then you need to turn the idle speed down again. Continue to do this until you can get the idle down to a nice low smooth idle speed. At that point you will be able to adjust the idle mixture. At the high speed it is running right now you are pulling gas through the high speed circuit of the carb in addition to the idle circuit. You have got to get the idle speed down and the mixture down. Here is a tip, with the engine off turn the idle mixture screw all the way in gently until it stops, then back it out two turns. That will get you in a good starting position for setting the carb. But like I said, if someone has jammed that screw in then setting the mixture will be very hard to do, if possible at all.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: engine

Unread post by rupert's » February 12th, 2021, 2:13 pm

rickf wrote:
February 12th, 2021, 9:26 am
Tighten it but if that screw was ever run in and tightened hard against the orifice then you will never really be able to properly adjust it. You should have a range from to lean to too rich and that should be at least a full turn of the screw. You mentioned the gas was cloudy and that is a problem. Gasoline should be clean and clear with some yellowish color to it. I don't know exactly what color yours will be over there but it is surely not cloudy. That is a sign of old or contaminated gas. That could be part of your problem. How old is the gas?

I just watched the video and it is running way to fast and way to rich. You did turn the idle down some and now you need to turn the mixture screw in until it smooths out and then you need to turn the idle speed down again. Continue to do this until you can get the idle down to a nice low smooth idle speed. At that point you will be able to adjust the idle mixture. At the high speed it is running right now you are pulling gas through the high speed circuit of the carb in addition to the idle circuit. You have got to get the idle speed down and the mixture down. Here is a tip, with the engine off turn the idle mixture screw all the way in gently until it stops, then back it out two turns. That will get you in a good starting position for setting the carb. But like I said, if someone has jammed that screw in then setting the mixture will be very hard to do, if possible at all.
Rick, I have followed your instructions

I start with the screw of the mixture tight and I take two turns, and I start to do tests but I do not get anything, the very black smoke is always present, with the screw of the mixture tight and when it is loose it also comes out very black, I have arrived to remove that screw and the engine has not stopped, it has only accelerated.

Almost at the end of the video I press it completely and the idle hardly varies ...

I think something has to be wrong inside the carburetor and maybe something else ...

https://youtu.be/ZEt4XpVNqpI

Edito: The gasoline is new, 95 unleaded, (now I know that I have to add an additive for lead, I found out yesterday) the gasoline has been in the tank for approximately 1 month and it is as you have described it, which was a bit dark is the one that came out of the carburetor.

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Re: engine

Unread post by rickf » February 12th, 2021, 3:20 pm

Ok, You have GOT to stop playing with the idle speed!!!!! Get it to a fairly low idle but where it is running steady and LEAVE IT ALONE!! Now, at the 5:15 mark it looks like you turned the mixture screw all the way in. IS correct and it was in as far as it would go? If it was then there are only two possibilities. One is the float is set wrong or the float is bad and has sunk. If it is the black composite float it cannot sink and it needs to be set at 9/32 inch. If the float is set correctly then someone has jammed that idle mixture screw in and destroyed the carb. Not much more I can say to help you on that one. You have a tapered steel needle and a measured orifice in the aluminum carb body. If someone jams that needle in then the hole is enlarged and it will be impossible to get the correct mixture. Check the float first. The carb will have to be taken off to do this so while it is off blow out all of the passages with carb cleaner and air. When you take the bowl off be very careful you do not lose the long brass jet that is in the center of the bowl and will usually fall out when yo turn the bowl over. There is a very tiny oring type gasket on this jet under the top part on the shaft, do not lose it. Some are already missing and I have run them without and had no issues but best to have it.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: engine

Unread post by rupert's » February 13th, 2021, 6:16 am

Right, at 5:15, it's all the way to the bottom, as far as the dock stops it. I'm going to start with the float, I think I'll have time to open it on Monday, I'll keep you informed. A greeting and thank you very much for your help.

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Re: engine

Unread post by rupert's » February 15th, 2021, 5:54 am

Today I have opened the carburetor, the float seems to do its job well, I have measured from the hinge to the paper gasket that the carburetor has and there is 7mm
Is it well measured?

On the other hand, I have seen that the hole of the inactive mixture seems to be forced, it is a little bulging towards the outside and there are some small cracks ... Does this mean that the carburetor no longer works?

Edit ... I have tried to cover the cracks and it seems that it has been working better for a while, less black smoke, and more white.

https://youtu.be/IjPELIpb13E

Un saludo
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