440 problems

[Ben.Ehrhart]

I having trouble getting my 440 running right again, and I'm hoping that someone can help. Here's the situation.
I had a cracked head (small crack between the valves on one side). It ran ok but it started hard, missed while idling, and didn't have full power, but it did pull OK. I got a new head, and the local machine shop did a valve job (new exhaust valves, the intake valves were OK but they machined them to match). I put it back together, and it started fine and idled good (no more missing), but I had no power. I couldn't pull out in 2nd gear on a flat surface. I thought it may ba a problem with the carburetor, so I got a rebuild kit and re-built it (it was due anyway). Now it's no better (no power) and it's running lean. It wants to run with the choke half on. No adjustment of the carb seems to make it right. I took the carb apart and went over it again to make sure nothing was clogged, but it seems to be OK. Any suggestions?

[mapaduke@yahoo.com]

HAVE YOU CHECKED THE COMPRESSION IN EACH CYLINDER?

[H-D]

Verify that the ignition timing is set correctly & that the centrifugal advance is functional. When you went through the carburetor, did you remove the emulsion tube & verify that the tiny orifices in it were open?

[Ben.Ehrhart]

Compression is good.
I put a new power jet nozzle in the carb that came with the rebuild kit, so it is clean.
I think the timing is right. I've actually tried adjusting it through the full range that it will run in, and the results are the same. The distrubutor has been apart and cleaned out and everything appears to be functional.

[57pilot]

Ben,

I'm not familiar with the carb on the 440 but assuming it is similar to the 420 carb it may be that the venturi is installed upside down. My 420 ran exactly as you described for your 440 after I rebuilt the carb. Drove me crazy before I discovered my blunder and that's not even the most embarassing thing I've screwed up.

Al

[Paul Buhler]

This may be a dumb question, but are your ignition wires connected correctly; meaning does the wire from #1 port on the distributor cap go to #1 cylinder, etc? I know that a mix up on some auto engines will allow them to run and even sound good, but won't allow the engine to develop any power - guess how I found this out.

[Ben.Ehrhart]

I double checked, and my plug wires are correct and the venturi is right-side-up. Any other suggestions?

[JD440ICD2006]

Check compression and valve settings.
Valve adjustment is done when engine is COLD. Cylinder needs to be at TDC of the COMPRESSION stroke, not the exhaust stroke. Once the piston is at TDC, adjust valves to .015, both intake and exhaust.
If this does not help, you have timing, air intake leak, or a head gasket problems.
Make a list of what you changed or took off, that will narrow down the problem if it was making power before you pulled the head.

[yellowcrawler]

I had a similar problem with no power and running with the choke halfway out. The venturi requires sealing to the housing to prevent sucking air from the vent opening to the bowl. Since the air bypasses the interior of the venturi, you won't pick up much fuel. I used aviation style permatex, which cured the problem. The avation permatex will allow you to take it apart again and is not affected by gasoline after it dries.

[Ben.Ehrhart]

I will try sealing the venturi to the carb body.
I'm beginning to wonder if my carb was mixed and matched and the TSX model number is not what it was supposed to be. If this is true, I may have gotten he wrong rebuild kit. Is there a way to match the crawler serial number to the original TSX model number?

[JD440ICD2006]

What is the number on your carb?

[Ben.Ehrhart]

The number on the carb is TSX769. This model number was apparently used on some Ford tractors of the same era, but I have not found anything that references this number for the 440IC. I think it should be TSX 777, 768, or 756. I'm assuming that these are the same casting with different configuration of jets, orifices sizes, and adjustments. Is this accurate? For what it's worth, the bowl is painted yellow, but the top (which has the number plate on it) is painted red. This leads me to believe that it has been pieced together by a previous owner.
At any rate, it did run better before I replaced the cracked head (with no other variables), and rebuilding the carb (possibly with he wrong kit) made only a marginal improvement.

[Gil]

Are you certain that you are getting a continuous unobstructed flow of gas? Disconnect the gas line from the carburetor and see if it will flow steadily to collect a gallon or so. You might also disconnect the air intake hose to be sure you do not have a blockage in the air filter. With restrictions in either air or gasoline, the engine may start and idle but not develop power.

Can you rev the engine up with it in neutral?

[1010crazy]

I would be looking in the head for your problem. If it ran OK before with the cracked head the problem is likely something that has been changed. I would check valve clearance and proper seal of the valves. Did you replace the valve springs? are they strong? head gasket sealed well? Does it spit fuel out of the carb throat? that would lead me to a leaking intake valve. I am sure you checked these things already but I would check again and maybe again It's easy to asume new is good but we all get burned on that one.

[Ben.Ehrhart]

I appreciate everyone's input. The fuel supply is good. My dad has a 40, and we put his carb on instead of mine and it ran much better. It wasn't perfect, but the governor linkage is different, so we has to work the throttle manually, and we didn't adjust the needle valves to tune it in. What that tells me is that my suspicions were correct that the previous owner had mixed and matched carb parts. Mine says that it's a TSX769, but I don't think that's the correct number for a 440. Can anyone tell me what number carb it's supposed to be?