Holley carb question

mikewood869

Well-known Member
On our 3000, is there any way to adjust the carb without having to pull the carburetor apart? The tractor has been running rich.
mvphoto32567.jpg

That spark plug is from a John Deere A, but the 3000 spark plug looked a lot worse than that (much darker and more carbon.
 
I will tell you what my carb rebuilder said about Holley carbs on Ford tractors. He is as good as I have seen, being a retired toolmaker. He said he has about a 50-50 chance of success for rebuilding one of the Holleys. He suggest buying a new Zenith (at around $600) and installing that on your Ford. Probably not what you wanted to hear. I went through this with my next door neighbors tractor...He feels some of them can be fixed, some not...
 
(quoted from post at 02:02:44 03/08/19) I will tell you what my carb rebuilder said about Holley carbs on Ford tractors. He is as good as I have seen, being a retired toolmaker. He said he has about a 50-50 chance of success for rebuilding one of the Holleys. He suggest buying a new Zenith (at around $600) and installing that on your Ford. Probably not what you wanted to hear. I went through this with my next door neighbors tractor...He feels some of them can be fixed, some not...

The tractor runs alright, but if you want power NOW, you can start to hear the tractor puff though the carb. This is the tractor second Holley carb, the first one had a hole in the side of it and this second one gave the tractor more power. The second carb came off of a industrial tractor (the carb was yellow).
 

Check the compression, adjust the valves and confirm the basics before you condemn the carb...

I don't know how many variations there are of those carbs... I have never seen one that could not be repaired it did take me a few to get a handle on'em tho they are a different animal from you standard run of the mill updraft carb...

Great carbs and in my opinion can not be beat like any-other engine they need a good solid foundation...
 
Bingo, Hobo.

The Holley is a more efficient (economical) and sophisticated carburetor than other Ford tractor carbs. It is also less tolerant of improper rebuild work.

Dean
 
Verify that other systems, especially ignition, are spot on before looking to the carburetor.

Also verify that the choke is opening fully, the air cleaner is clean and not restricted, and both centrifugal and vacuum spark advance are functioning properly.

If all is good, check float level. The Holley carburetor is sensitive to float level adjustment.

Dean
 
(quoted from post at 02:39:44 03/08/19) Verify that other systems, especially ignition, are spot on before looking to the carburetor.

Also verify that the choke is opening fully, the air cleaner is clean and not restricted, and both centrifugal and vacuum spark advance are functioning properly.

If all is good, check float level. The Holley carburetor is sensitive to float level adjustment.

Dean

The tractor has spark (clean at the moment and gaped the plug, around a running hour ago or so) the choke is fully open, the tractor has a new-ish air cleaner (around 50 hours, the worse the tractor has done was wood chip for 30 hours), we ended up plugging the line for the vacuum advanced because you couldn't get parts for it anymore, I have not checked the float level because I don't have the gaskets or parts for the carb if something was to go awry. The throttle rod is loose, but I have been tightening up the 9/16 nut at the bottom. The electric ignition seems to be working, but I might need to replace my key switch. When buying key switches at the NH parts dealer, I was informed that they are having problems with key switches. Over the fall we ended up losing the key for our Ford 8n, so we switched the key switch out with a old from the 3000 (wasn't a year old) and that one bit the dust a month ago.
 
(quoted from post at 02:22:48 03/08/19)
Check the compression, adjust the valves and confirm the basics before you condemn the carb...

I don't know how many variations there are of those carbs... I have never seen one that could not be repaired it did take me a few to get a handle on'em tho they are a different animal from you standard run of the mill updraft carb...

Great carbs and in my opinion can not be beat like any-other engine they need a good solid foundation...

The compression is at the minimum I guess (just guessing between 90 and 115), the rockers are clattering, but if you touch them while the tractor is running that sound goes away. When we did the valves, we tightened them down till the tractor stopped clattering, but that made the tractor run worse. When making doing the valves, we didn't know where tdc was, so we ended up guessing (long screw driver down the spark plug hole or rod). When we did a clutch job on the tractor, we ended up taking the flywheel off and probably didn't put the flywheel back on in the right spot (could be 180 off or who knows. As far as I know the motor has never had a rebuild (the hour meter probably has reset a few times).
 
Adjust the valves by the book, don't guess. You dont need burned valves.
The flywheel can only fit on one way.
 
Do you have a manual? Get one, well worth the investment even just an I&T is a big help. Sounds to me like you're doing a lot of guessing. The carb has a spring/vacuum operated accelerator pump that could be the problem.
 
The timing Mark's are there, but can be
hard to see. Maybe a shot of brake
cleaner and a rag, then rub with chalk.
 

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