Tractor Engine Quits After A Couple of Hours

rlk · Oct 3, 2002

I have a gas MF 35 that I have had for about 15 years. I bought it used, and have used it extensively since buying it. The engine has developed a problem that has me stumped.

A week ago, after running it for about 3 hours raking the area around the pond with a landscape rake, the engine quit. Sounded like it was out of fuel. I messed with it for a few minutes, then tried to start it again. Started fine and ran for about 5 minutes then sputtered again like there was trash in the fuel line, or like it was giving out of fuel. This time I pulled the choke out a little, and it recovered for a few minutes, then sputtered again. Pulled the choke out again for a second or too, but this time it did no good - the engine quit.

Removed the gas cap to make sure there was fuel in the tank. Apparently the tank was pressurized because there was quite a sound as either air escaped the tank, or rushed in. Saw there was plenty of fuel in the tank, so removed the sediment (spelling) bowl. When I did this, the fuel gurgled a few times, then fuel ran out. Put the bowl back on, and the engine started fine. Made it to the shop and let it sit over night.

Next morning it started up fine and ran for a couple of hours before doing the same thing again. Engine sputtered some, I pulled the choke a few times, it recovered for a short time, then quit. Gas tank was pressureized. Removed the sediment bowl, gurgled again, then fuel ran out. Engine started up, but would only run for 20 seconds or so before cutting off again.

I decided I had trash in the fuel, and/or something was wrong with the sediment bowl assembly.

Found a replacement sediment bowl assembly. Took the old one off, drained the tank, then installed the new one. Also installed a new gas line to the carburetor. Engine started and ran fine for the rest of the day. I thought the problem was solved.

Next day, after a couple hours of raking, same thing happens again.

Talked to a Massey Furgeson parts person, and he suggested rebuilding the carburetor. Yesterday, I picked up a kit and rebuilt the carburetor. Today, after about 3 hours, the same scenario takes place again.

Finally make it back to the shop and let it sit outside while I talked to my neighbor. After about an hour, it started and ran long enough for me to get it into the shop. It might have run longer, but it was the end of the day, and I was tired of messing with it.

Originally I thought the problem was fuel related because pulling the choke out some when it sputtered would help it run a little longer. Now I'm not too sure.

Could it be the condenser or coil is getting hot and failing? These are not very expensive items, and are fairly easy to replace.

Could it also be vapor lock? Not sure how to fix a vapor lock problem on a tractor, but I used to have a Volkswagen that would not start when it was hot. Everyone said it was vapor lock - ended up trading it without ever fixing it.

Before doing anything else, I wanted to see if any of you had an idea what the problem may be.

MossRoad · Oct 3, 2002

On my IH2500B I have an electric solenoid that shuts off the fuel when the key is turned off. The thing gets flakey and has to be replaced every few years. It gave similar simptoms. Do you have a solenoid like that? Just a thought.

chim · Oct 3, 2002

Just a thought. From what you said - "air escaped the tank, or rushed in" are you sure tha tank was pressurized, or is it possible it was under a vacuum? If the tank can't breathe, mebbe the engine can't draw fuel. That would kinda explain why the choke made a differnece for a short run. This could be ruled out as a problem by removing the fuel cap when it dies the next time. If it still won't run, forget this and look for something else......................chim

Casimir · Oct 3, 2002

rlk--

It does sound like a fuel problem, rather than an electrical problem. You say that when you remove the sediment bowl, it gurgles, then gas runs out and it will start and run again. Sounds to me like you may have something floating in the gas tank that gets sucked up against the intake, creating a vacuum in the line. When you allow air in the other end of the line, it may be back flushing whatever is clogging the intake inside the tank.

But you also mentioned that the tank seems pressurized or air rushes into the tank when you remove the cap. Is the cap vented? If it is, and is supposed to be, something may be clogging the vent in the cap. As long as there is plenty of air in the tank, the fuel could flow to the engine until enough vacuum built up in the tank to keep the fuel pump from pulling the gas from the tank.

I would check to see if the cap is vented or the tank is otherwise vented, with something clogging the vent. A new fuel cap may be cheaper and faster to change than a coil. Next would be to check for debris in the tank that may be clogging the fuel line intake. This might require removing and draining the tank to get any loose debris out of the bottom of the tank.

Good luck. These things can really be frustrating. /w3tcompact/icons/hmm.gif /w3tcompact/icons/sad.gif

Hydraman · Oct 3, 2002

Try loosening the gas cap just a bit-- sounds like a POSSIBILITY that your tank is going on a vacuum-- saw this happen w/ one other outfit one time. My father had a '55 plymouth that did this when we were all on vacation. He found a good man that pointed him to the problem!! The rushing air sound and the gurgleing sound are what make me suspicious. Good luck!

rlk · Oct 3, 2002

MossRoad

Thanks for the suggestion. No solenoid that I'm aware of that controls fuel. The gas line is a straight shot from the sediment bowl to the carburetor.

rlk · Oct 3, 2002

Chim, Casimir, Hydraman

Thanks for your replies. Sounds like the consensus is the tank is getting somehow going on vacuum, or perhaps trash in the tank. I drained the tank when I replaced the sediment bowl, but did not flush it. If it is trash in the tank, I don't see how that could cause a vacuum, but you never know.

I have never changed the gas cap. Looking at it previously, I thought it looked a little wierd in that there are no holes in it. Not sure how air is supposed to enter the tank to replace the fuel being burned. I have not found anything else connected to the tank that looks like a vent.

The air I hear must be air rushing in to relieve the vacuum. Tomorrow I'll try running with the gas cap loose to see if that helps.

Again, thanks for all your help. It is really good to have a place to discuss problems like this.

Muhammad, thanks for providing such a great site!

karmakanic · Oct 3, 2002

a few thoughts Bob,

Chim is right on about the tank venting. See if it makes a difference if the cap is removed.

Does the tractor use a fuel pump, or is it gravity feed to the carb? Fuel pump could defnitely cause the problem.

Some ignition system problems could also cause the symptoms you describe. Pulling the choke out richens the mixture which reduces the load on the secondary part of the ignition. A marginal coil for instance might be influenced by this. I've never seen a condensor cause it, but I'm old enough to not discount anything when it comes to engines. But condensor would usually cause arcing of the points,,,might look for a "mountain" on one side of points, and valley on other for evidence of weak condensor.

If removing the fuel tank cap doesn't have any effect, I'd go to the auto parts store and buy one of those inexpensive "spark testers". You put these in the circuit between distributor and spark plug. See if you're loosing ignition or fuel when the problem occurs, and go from there.

BTW, a quick note about rust in the tank. Most radiator/gas tank shops offer a process to seal the insides of the tank with a plastic sealer. Any older farm vehicle needs this done, especially those with gas engines, or you'll be fighting continual rust in the fuel system problems.

HTH,
Dave

bgott · Oct 3, 2002

If the tank is like the one on an 8N it'll have a vent built into the top of the tank, not a vented cap. They did this to keep gas from sloshing out when the tank is full. A vented cap is not designed to have gas sloshing on it. Think about what happened on those old cars when you over filled them. The vent on the 8N is a hole in the top of the tank with a steel bowl welded over it. The steel bowl has a hole at the opposite end from the hole in the tank. That way any gas that sloshes out of the hole in the tank can drain back without running down the outside of the tank. Stick a vented cap on it, or drill a little hole in your old cap and see if the problem goes away. Make sure the tank is only half full, most people run the vented cap and ignore the drips but it could possibly drip down on your exhaust pipe and form the subject of a whole 'nother thread.

TBone · Oct 4, 2002

My guess would definitely be a venting problem on your gas tank. I grew up with an 8N ford that did that very thing. Cleaned the vent out and it was OK.

This website <A target="_blank" HREF=http://hometown.aol.com/bigdean62/index.html>http://hometown.aol.com/bigdean62/index.html</A> will connect you with a guy that was a Massey mechanic for 27 years and knows his stuff about the older tractors.

Good Luck!

TBone