Where do I start.

[leerenovations]

Yesteday I spent about 3 hours mowing with the my 48. I had to idle back the tractor to kill a copperhead. WHen I got back on her and throttled her up again, she began running rough. I took her back to the shade tree and killed her. I noticed that some fluid that looked like hydraulic fluid was sizzling under the touch control unit where it bolts onto the bell housing. I felt in that area and it was frying pan hot, but the other side of the tractor in the same area was no where near as hot. I started her again and tried to work her and she was still running rough so I shut her down for about 2 hours. Later I made sure the radiator wasnt full of ebdris and added water until it ran out (I know they regulate temselves). But she still ran rough.

What could have caused this or is causing this. And where do I start to look to find out what is wrong.

[Eugene]

Probably ignition related, fouled spark plug, etc.. Suggest complete engine tune up.

But first, check the fuel flow, through the carburetor and clean the main carburetor jet.

[Mike in Louisiana]

if you pull the choke out does it the motoe smooth out???

[TJG]

Did the copperhead bite her?

Todd

[bythepond88]

I'm guessing coil for the rough running. I had the same problem for a while - If I idled her down for a while (potty break) after an hour or more, she would run rough when I tried to resume mowing. Turned out to be a failing coil.

[leerenovations]

if you pull the choke out does it the motoe smooth out???

Yes it does, but only if I choke it a little. Like abut a 1/8 choke. But it dosent help the power, when I try to move it, she lugs a little.

[Barnyard]

if you pull the choke out does it the motoe smooth out???

Yes it does, but only if I choke it a little. Like abut a 1/8 choke. But it dosent help the power, when I try to move it, she lugs a little.

Sounds like you might need to clean the metering jet as Eugene suggested. Remove it and run a soft copper wire through it and blow it out with some carb cleaner. You may be getting crud into your carb.

[leerenovations]

OK, I cleaned the metering jet. SHe starts right up without choking. But when she gets hot, she began to run rough almost if she was missing. Could this be the coil? My Cub has the origial magneto start with the 6 volt battery so which coil do I buy?

[bythepond88]

when she gets hot, she began to run rough almost if she was missing. Could this be the coil

Yes, that is a symptom of a failing coil.

[Hengy]

But why would it be sizzling hot all the way back at the TC unit with a problem in the engine? Could there be something messed up in the TC unit that is causing it to run through the pressure relief valve all the time? This would really suck the power out of the tractor and would also make the TC unit get hot. Did you try cycling through the TC? I'm just keying on the reasons for it to be hot all the way back at the TC with all of that cast iron between the engine and that section.

When the TC area was sizzling, was the radiator boiling?

[leerenovations]

No, the radiator was fine, not hot at all. I just rebuilt the TC pump and was using it to raisde and lower the sickle mower with no problem at all. Could it be that the oil pump is getting a little weak? ANd maybe not pumping oil enough, or does engine oil even run back that far?

[Hengy]

No. The oil is confined to the engine block. I know that Merlin has a bit of an adjustment needed on the TC and if I run the lever all the way into one extreme or the other, the TC continues to try to raise or lower and the engine pumps the fluid through the pressure relief valve. It will bog the tractor down to the extreme and make it seem really low on power. If I move the lever slightly back towards the middle, the bogging stops and everyone is happy. I know that I need to make the adjustment that they talk about in the TC manual, but just haven't gotten a "Round Tuit" yet, so I am just working around it.

Try moving your TC lever to the middle of the quadrant and see if the tractor runs better. The only way that it can get sizzling hot under the TC is if there is something going on with the TC. No engine oil there.

Mike

[Matt Kirsch]

If anything a weak hydraulic pump would prevent the oil from getting sizzling hot like that, because it can't develop enough pressure.

[Smokeycub]

Could there be something messed up in the TC unit that is causing it to run through the pressure relief valve all the time? This would really suck the power out of the tractor and would also make the TC unit get hot.

Good observation Mike, that would do it. I wanted to add that there should be an audible hydraulic noise if that's what's happening. Does it have an under slung exhaust? ...that's maybe a little to close to a hydraulic line - maybe?

[leerenovations]

No underslung exhaust, I like it up where I can breathe the exhaust and make the day go faster. Well, I just rebult the TC pump, could I have put something in wrong? ANd even though I just rebuilt the pump, it worked great for about an hour then acted like it was running low on fluid again. ANd it raiees the hydraulics just fine, but it bogs the tractor when trying to lower the hydraulics. All the way up or all the way down, the front rockshaft does that rocking like its low on fluid. Could that really bog the whole tractor down?