4 cyl 4000 - Lost Power - How to Troubleshoot?

Hello,

My 1964 4000 gas lost power. It had a backfire and then coughed a bit and had trouble starting after that. The air cleaner had a bunch of water mixed in with the oil and the spark plugs were very black. Also, that carb main jet was set to 5 or 6 turns out.

I've replaced the oil in the air cleaner, changed the plugs and set the carb to about 2 turns. I will start and run, but barely has enough power to move itself.

Can someone give me some guidance on tracking down what the problem is?

Thanks,
Jerry
 
"barley has enough power to move itself" -- 1 cylinder? 2 cylinders? Choke or no choke?? no throttle, some throttle???
 

Get a compression tester. It is not much money. Two turns out is just fine unless you are entering a tractor pull with it.
 
I've got a 1963 year model 4000 with the carb set at 2.25 - 2.5 or so turns out as I recall. It runs fine. Start with basics such as fuel, spark, air, timing, compression.
 
That engine will run on 3 cylinders. Make sure you have good spark on all plugs. Might be fuel screen blocked.
 
(quoted from post at 04:17:46 09/22/19)
Get a compression tester. It is not much money. Two turns out is just fine unless you are entering a tractor pull with it.

I'm trying to find a compression tester on Amazon, but all the ones that thread in list metric adapters. I wouldn't think this engine would have metric threads for the spark plugs.
 
(quoted from post at 17:09:39 09/22/19)
(quoted from post at 04:17:46 09/22/19)
Get a compression tester. It is not much money. Two turns out is just fine unless you are entering a tractor pull with it.

I'm trying to find a compression tester on Amazon, but all the ones that thread in list metric adapters. I wouldn't think this engine would have metric threads for the spark plugs.

I just googled it and the forum discussion that came up said that spark plugs have been metric since the 1930s.
 
Before you do anything else put an inductive timing light on it and make sure it is in time. If you don't have one get a loaner from one of the big auto parts store. They should have one. This is just to make sure the distributor has not lost timing.


If this checks out take a look at the points and under the distributor cap. Make sure the points are clean and there is no condensation or carbon tracking on the cap. While it is running in the dark see if you have a strong spark from the high tension lead coming from the coil.

It is unlikely the rings would go bad suddenly, but check the oil and make sure you have not blown a head gasket. Also you can smell antifreeze burning in the exhaust. I smells like celery.

It is possible to have a leak between cylinders without water entering the cylinders. A compression gauge would tell.

If all the rest checks out you might have to take the valve cover off and see if the valves are properly timed and the camshaft gear has not jumped.
 
(quoted from post at 17:50:18 09/23/19) Before you do anything else put an inductive timing light on it and make sure it is in time. If you don't have one get a loaner from one of the big auto parts store. They should have one. This is just to make sure the distributor has not lost timing.


If this checks out take a look at the points and under the distributor cap. Make sure the points are clean and there is no condensation or carbon tracking on the cap. While it is running in the dark see if you have a strong spark from the high tension lead coming from the coil.

Just now getting back to this. I haven't found a timing light yet, but the rotor doesn't stay on the shaft properly so it stays keyed into the flat spot. I'll have to see if I can find one locally, I don't know if Tractor Supply of NAPA has it or not.

This post was edited by Jerry Ward on 08/22/2021 at 01:29 pm.
 
Probably best to start a new thread, as most folks on here still use the "classic View" so they won't even see your new post. Are you missing the clip that goes under the rotor?
 
(quoted from post at 16:41:17 08/22/21)
There is a clip there, but I'm not sure how it does anything


The clip is supposed to fit tight to the shaft and the rotor fairly tight onto the clip.
 

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