runs rough after about an hour

[SydKen]

Hi Guys,
I got my YM3000 out for the first time this season today and after running for about an hour it began to run rough. I started noticing it and it slowly got worse. Came home this evening and it started right up and ran great but after about an hour it started doing it again.

Any ideas?

 

[carpenter383]

This may not even be close, but make sure the feul cap is vented good. Other than that make sure it's not getting hot

 

[LMTC]

"About an hour". If it's closer to 20 minutes each time I would consider injector, then head. I've seen both (when damaged) create rough running when hot, but not cold. If it's a vent issue in the fuel tank, it should eventually just shut down until the tank is vented.

 

[RickB]

Change the fuel filter, and while the filter is off, check the fuel flow from the tank to the filter head. Save the gloom & doom catastrophic stuff until the simple and cheap has been eliminated from suspicion.

 

[SydKen]

I will pay close attention to the time today as I finish cutting the grass, but I'm pretty sure it was more like 45 minutes to an hour instead of 20 minutes. I just replaced my fuel filter at the end of last season so i don't think that's it. I am curious about the venting though. I assume that if it starts running rough and I loosen the cap on the fuel tank it will smooth out if it is a vent issue?

 

[RickB]

Could also be about a 75% mix of gasoline in the diesel fuel. They will run more or less OK until they get warm.

 

[LMTC]

Change the fuel filter, and while the filter is off, check the fuel flow from the tank to the filter head. Save the gloom & doom catastrophic stuff until the simple and cheap has been eliminated from suspicion.

The fuel filter was elminated when it ran for an hour, ran rough, then ran well when cooled down. I have never seen a fuel filter issue cause repeated rough running after an hour (or even 20 minutes) only to clear up when the engine cools down, and then reoccur when hot. It's just not an issue that fits those symptoms. The clearing up when cool is a major factor...it means the source of the problem is not consistent, i.e., it probably has to get hot to mal-perform.

 

[RickB]

Opinions differ. Cylinder head problems don't come and go, in my experience. A mostly plugged filter or restriction in the tank outlet are common, easily cured, and are very much within the list of possible causes. Prudent troubleshooting begins with the easy, cheap stuff. I can't tell you how many times I have heard " Don't bother to check the fuses, I did and they are all OK" only to find a blown fuse. Last year's fuel filter is still last year's fuel filter, and last time I checked, cheaper than a head gasket and easier to change.

 

[kenmac]

do you have a temp light / gauge ?? If light. check to be sure temp light/ sensor is working properly

 

[LMTC]

Opinions differ. Cylinder head problems don't come and go, in my experience. A mostly plugged filter or restriction in the tank outlet are common, easily cured, and are very much within the list of possible causes. Prudent troubleshooting begins with the easy, cheap stuff. I can't tell you how many times I have heard " Don't bother to check the fuses, I did and they are all OK" only to find a blown fuse. Last year's fuel filter is still last year's fuel filter, and last time I checked, cheaper than a head gasket and easier to change.

Opinions do differ.....I have on several occasions seen a tractor with a bad head run well for 20 minutes or so, then run badly. On cool down, same pattern. I wouldn't call that "come and go", I would call it a repetitive pattern. But then your experience may go well beyond mine with these tractors.

 

[SydKen]

do you have a temp light / gauge ?? If light. check to be sure temp light/ sensor is working properly

I do. It comes on when I turn the key to start the tractor and has worked once when I was low on coolant. I had alot of white smoke when I tried to start it and had quite a bit of trouble getting her started. My cover came off the exhaust pipe so I am assuming that I had moisture in there somewhere. Could that have been a problem?

 

[Egon]

There have been several other threads here with a similar type problem. If my memory is correct those ended up having fuel tank debris moving around and blocking the fuel line outlet.

 

[EddieWalker]

I had a similar problem with a jeep. When it warmed it, it ran rough, lost power and sometimes it died, but mostly, it just ran really rough. It turned out that my exhaust was plugged up. Clearing that fixed all my problem.

That was with a gas engine, so it may or may not be of any help with a diesel engine.

Eddie

 

[tallyho8]

I do. It comes on when I turn the key to start the tractor and has worked once when I was low on coolant. I had alot of white smoke when I tried to start it and had quite a bit of trouble getting her started. My cover came off the exhaust pipe so I am assuming that I had moisture in there somewhere. Could that have been a problem?

My YM1802 has a temperature guage and a light. The light only shows the water level in the radiator and comes on when the water is low. If the engine overheats, this light does not come on. You must watch the temperature guage if it has one.

 

[kenmac]

I would add a temp guage .. My 3110 has a temp light. I have no idea what temp the engine runs. But the light has never come ( I've tested it to be sure sending unit & light work) Never had any engine problems.. sounds like you have a over heating issue

 

[chriswheeler]

You might want to try getting it warm and to the point where it starts running rough. With the engine still running, losen the fuel lines, one at a time, going to the 3 injectors. If there is a injector problem ( plugged injector ) the engine will not run rougher as the line is loosened. If the injector is OK, generaly the engine will run rougher. You could have one of quite a few problems, most likely fuel related. Don't forget to check the fuel return line to the tank from the injectors, make sure there is a small flow back to the tank. Might also want to check the water pump. Cold engine, remove the rad. cap. Start the engine and look inside for a flow. The YM3000 does not have a thermostat, full flow at all times.
Chris

 

[blackd]

Does your tractor have a "lift" pump? Lifts fuel into the filter. Sometimes when they start to go bad, they will pump fuel but not enough to keep it running well. Mine went bad and it took better part of a year to get bad enough to find the problem. First signs were when going up a steep hill.

 

[chriswheeler]

YM 3000 does not have a lift pump.
Chris

 

[valley]

Greetings, We don't want it to be a head gasket, too much like work! If it is a gasket it should show up as loss of water in the radiator or bubble or oil in the water, thats what I have seen. If it is venting to the out side you should be able to feel that around the side of the head. Do you agree?
Just curious when are your valves in adjustment,not too tight? I have seen an exhaust valve that is too tight stop an engine when it gets warm on small one cylinder engines. Hope this helps. Richard

 

[valley]

SydKen, On your post #11 you said you had a lot of white smoke come out the exhaust when you tried to start the engine. This happened just the one time? Richard