carb settings

This is the first of many questions about my 39 A. The tractor seems to idle ok but lacks high rpm and hunts a bit. The tractor has a new carb and im trying to find out what the proper settings should be. I have set the governor linkage so that with the power lever full open and the carb wide open the linkage mates up nicely. I should note that when the A is off and the power lever is at at idle there is some slop in the governor arm assy but i dont know if this is normal. Any help would be great. thanks

Was the tractor running before? If so, did it run up to high idle then?

There isn't much to adjust on the carb. You say it's new, so I'm assuming its a Zenith 14007 or something similar for gas only. If so, there's only the idle stop screw on the throttle lever and the idle mixture screw at the throat of the carb. The latter should be adjusted 1-1/4 or 1-1/2 turns from being bottomed out as a starting point for finer adjustmdnt once it's running.

Did you feel any spring tension on the governor arm when you synched it with the carb. There should have been a little, which would indicate that the governor spring is at least there and functioning. The slop you mentioned with the engine stopped and speed lever at the lower end is quite normal, and I really don't think your governor is going to be the problem.

I'd sooner suspect restricted fuel flow or stale fuel. It could also be that the impulse coupler on your mag is stuck and not advancing to running speed.

When i got the tractor it had been sitting a few years. She wouldnt start for me and long story short the oil had been washed away from the cylinders when i was trying to prime the engine thus not creating enough suction to draw up the fuel air mix. With my inexperience to the ole gal i gave her a new carb and intake manifold. i finally got her running but in hindsight i probably didnt need to get the carb. I have the carb set at or near the settings you mentioned. Yes there was spring tension on the gov and i actually have peeked inside to inspect its weights and springs, all looks good and is free moving. the fuel line has been checked for obstructions and is clear . The fuel is fresh and the fuel strainer is new and clean. With the tractor running at idle i can take hold of the gov/carb connecting linkage and run the engine wide open, the gov fights back as i think it should but i cannot achieve the same hi power with the lever. maybe some of that babble will help further. Thanks for the help. Im off to take a look at the mag.

Take a look at the front end of the rod that runs from your speed control lever (the one back at the seat) where it connects to the governor. There should be two springs at the front end, one on either side of the connection to the governor. Are they both there?

Just one spring. The speed change lever is connected to the rod by a square steel piece about 3/4 thick which has a small pin and a cotter pin. The spring rides on the rod forward of the square piece then a washer then a cotter pin. I looked at my manual and it shows the gov. breakdown but not the linkage.

That'd be the first thing to fix. There should be one spring ahead of the block you describe, and another behind it. . The one to the rear shold be held in place with a washer and cotter pin just like the front. IIRC, the springs had different part numbers indicating different lengths and tensions. I think CaseIHNH still stocks them. If you can't find them locally, try Bermuda Ken at external_link.

The governor is all about springs balancing against each other. The two inside are critical, but having those two on the rod in good order may well fix it, and you won't have to go tearing into the guts of the governor.

And the missing spring would be one explanantion for your engine not responding to the adustment from the speed control. Without both springs your rod is just floating through the block that connects to the governor. To confirm, try throttling it up using the arm on the right side of the governor, where the block connects, instead of the arm on the left.

My parts book is a reprint, but the rod and springs are on p. 79 in mine as chassis parts.

You said your A was a '39, so that rear spring MAY not be an issue. My book shows the rear spring only for serial numbers 2690 and up. If yours is earlier than that, we may have to look for another answer.

That said, the numbers for the springs, if they help your parts guy look them up are

53393D (rear)
51300D (front)

If you do wind up replacing them, it wouldn't hurt to recheck the synch between the arm and throttle rod on the left side as you did before.

Thanks for the info. I'll get those springs on order, who knows if the one installed is correct. I just went out and fired her up and at idle there wasnt much control or change of rpm using the speed change lever on the right. Is there a good manual out there that i should have? I have an I&T shop service manual but seems to lack info here and there. The rod that connects to the speed change lever at the gov end is slightly bent and im wondering if thes is norm, a good pic would be great. Thanks again

The construction of that arm on the right side isn't such that it would bend out of shape under any stress on the system in any way that would affeect it's forward/reverse functional operation - basically a flat bar, so likely isn't a problem. It does have an offset lef to right, but is otherwise a straight bar on the input shaft. I can't get a picture of it straight on. The governor housing obscure it from the right, and the generator and belts and pulleys from the left.

Here's some pics. The first is on my BN, the second is on my Super C (same setup, as long as your A is above that serial number 2690).

[I'm borrowing a friend's site to post these, so they'll disappear from his server in a couple of days. If they are of any use to you, best to copy them now!]

I had a similar problem on my cub. The holes where the spring attached were worn and the throttle didn"t respond to the throttle lever until it was opened up about half way. To solve this problem, I installed a turnbuckle in the rod going from the throttle lever to the governor thus making it adjustable. Now it works as it should. rw

Well i found the sn, its 30973 so i guess she needs 2 springs afterall. Thanks for the pics they helped. is there a manual u would recomend other than the I&T for the future.

I tried sending an email through YT, but hit a blip in sending it(though I thought I got back around it), so it may not have gotten through.

I don't know what you have already for manuals. Long and short . . . I&T is good. For each of my tractors I also keep (sort of in ascending order of their usefulness, since you already have the I&T) . . .

1) the IH Operator's Manual, excellent for routine maintenance and adjustments down to the level of ignition timing, valve adjustment . . . Definitely a "must have", the basic level book that also includes wiring diagrams;

2)the IH Blue Ribbon Service Manual -- LOTS of (read "mostly") overlap with the I&T but has the advantages of being only about your tractor so you don't have to weed out/wade through the others, and generally has more illustrations particular to your tractor. The I&T and the IH manuals each have little tidbits in them that the other doesn't -- I've found it very useful having both;

3) the parts catalog. Can't say enough about its uses. A small part springs out when you take something apart and you cant find it? You can see what it is and know what to look for in the corners of your shop floor where those things go. Get a blank look from your CaseIHNHFord counterman when you need a part? You can give him the number. It's basically a book of exploded views of each subsystem or component on the tractor, each with a table of part names and numbers, that is very handy in noodling out how things are put together and therefore how they come apart. Indispensable if you plan now or ever have the need to really get into the guts of her.

HTH

Back again, I was able to purchase an entire governor rod assy cheap. I have installed the rod and require info on the carb settings. The carb is a zenith and has a idle adjusting screw, a main jet adjustment and a throttle stop screw. Also i have messed with the governor speed change lever stop and the governor bumper spring but cant remember where the settings should be. Thanks in advance!