Oil & Fuel MF135 cyclically cutting out

[MabouRidge]

I have a 135 MF with a 3 cylinder Perkins gas engine. I did a short bit of rototilling and was heading back to the barn and noticed that around every 3 seconds or so the engine was dieing out - the sound of the engine would momentarily become quieter and it lost a bit of power, then the engine would pick up again and run normally. Anybody have any ideas or suggestions?

One possibly relevant issue is that there has been some construction going on in the barn in the two weeks since I last ran the tractor. Chip board and pine boards are being cut in the barn, then delivered to another room in the barn to keep the dust out of the more finished part of the barn we are working on. So sawdust is being generated in the relatively confined space of the barn main floor (which has a high empty hay mow above it where dust can also circulate to). Also, the gas tank has a vent cap like you have on a furnace oil tank which means it is not a solid seal and appears to be meant to breathe (custom tank on it because it was adapted from diesel, to propane, to gas engine). My brother suggested that I should consider tying a plastic bag around the vent cap when I'm not using it to keep dust particles out of the gas. Anyway, does this sound like it might be a dirty fuel issue of some sort clogging up a valve somewhere? In other words, a dirty fuel issue caused by being housed in a dusty environment with a porous seal on the gas tank?

The distinguishing aspect of my problem however is the cyclical nature in which the sound and the power of the tractor is cutting out. If anyone has any ideas what part of the tractor might be causing this, I can look into those suggestions tomorrow when I go to the farm again. Also, any suggestions on what I should do to remedy said problem would be welcome as well.

Regards,
Paul Meagher

 

[MabouRidge]

Sometimes writing out your problem helps you to search for the answer in the forum.

One possible answer to my problem might be found on this thread:

http://www.tractorbynet.com/forums/.../206170-warm-engine-stall-mf135-perkins3.html

Specifically, this sounds relevant:

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Sounds to me as though the fuel system has a clog somewhere; when not running, enough fuel trickles through to build up a reserve (carb bowl, etc.) to run for a while, but the small delivery rate can't keep up once it's running so it runs lean and then stalls. Let it sit, process repeats....

Classic symptoms of a mostly-clogged filter, fuel pick-up, carb passage, or other susceptible part. Could even be a fuel line, degraded by ethanol in fuel.

Everything was fine initially, it just took the first hour or so of running for the culprit(s) to lodge themselves in the fuel system.

===============

Like I said, I was only running the tractor for a short while before the problem started to manifest itself. Stuff probably started to clog up after the dirty fuel started to accumulate.

Will probably siphon out the existing gas and check the filter and other routes along the way that might be most susceptible. This is my best guess on what the problem is so far.

Regards,
Paul

 

[Jerry/MT]

I have a 135 MF with a 3 cylinder Perkins gas engine. I did a short bit of rototilling and was heading back to the barn and noticed that around every 3 seconds or so the engine was dieing out - the sound of the engine would momentarily become quieter and it lost a bit of power, then the engine would pick up again and run normally. Anybody have any ideas or suggestions?

One possibly relevant issue is that there has been some construction going on in the barn in the two weeks since I last ran the tractor. Chip board and pine boards are being cut in the barn, then delivered to another room in the barn to keep the dust out of the more finished part of the barn we are working on. So sawdust is being generated in the relatively confined space of the barn main floor (which has a high empty hay mow above it where dust can also circulate to). Also, the gas tank has a vent cap like you have on a furnace oil tank which means it is not a solid seal and appears to be meant to breathe (custom tank on it because it was adapted from diesel, to propane, to gas engine). My brother suggested that I should consider tying a plastic bag around the vent cap when I'm not using it to keep dust particles out of the gas. Anyway, does this sound like it might be a dirty fuel issue of some sort clogging up a valve somewhere? In other words, a dirty fuel issue caused by being housed in a dusty environment with a porous seal on the gas tank?

The distinguishing aspect of my problem however is the cyclical nature in which the sound and the power of the tractor is cutting out. If anyone has any ideas what part of the tractor might be causing this, I can look into those suggestions tomorrow when I go to the farm again. Also, any suggestions on what I should do to remedy said problem would be welcome as well.

Regards,
Paul Meagher

While cyclic "cutting out", can be a fuel problem, it can also be a problem with the ignition. Specifically a worn distributor bushing, maladjusted points, loose wire, bad condensor, etc. As soon as the tractor starts doing this , IMMEDIATELY get off and check the spark. Pull the center wire from the distributor cap, hold it near ( ~1/4") a good ground and try a start. You should see a FAT, BLUISH-WHITE SPARK, the color of lightning. If you don't, then there is a problem most likely in the primary ignition circuit (battery to key switch to coil to distributor to ground).

If you have the requisite FAT, BLUISH-WHITE SPARK, then check the fuel delivery and the carb adjustments. I doubt that a dust environment would cause the problem since these machines were designed for field work. You could check the air filter for clogging but that's's not your stated sypmtoms (Clogged air filters restrict air flow and hence limit power. However these carbs are a "pressure balanced design" and they vent the fuel bowl to the air horn inlet so mixture isn't affected by restrictions in the air filter.)

Do these checks a report back on what you find.