Odd problem with throttle and water pump?

[JayIH]

My 154 IH Lo-Boy was running a little rough last time I had her going, but was idling a lot and hauling a heavy trailer. So before taking her out to mow today I decided to check the fluids. I popped the radiator cap and it was bone dry. I figured not good, so filled it up. Started it up and realized that there was no flow. I'm not 100% sure how the cooling system works on this tractor, keep in mind. I figured it may start once the engine gets to temp, so I got to mowing. About half way through it started jumping from idle to full throttle back and forth. I stopped and got off while it was running and noticed the bar that crosses in front of the engine and controlls something by the throttle body was jumping around, but the throttle was stationary. Looking at the tractor from the front the cable goes down to a little area, then seems to attach to something else which crosses to the other side of the engine, then back to the intake. Can anyone shed some light on this one? I'd greatly appreciate it.

[RaymondDurban]

Jay, there is no water pump on the C-60 engine. No Cubs have water pumps. The water circulates by convection. It is called a thermosyphon system. As the engine warm up, the hot water rises to the top of the engine and enters the top of the radiator. The fan cools the water down, and it falls in the radiator to reenter the engine at the lower water neck. The water level should not reach the top of the radiator. Some room is necessary for expansion. If you have the water level too high, the expansion will push the excess out, which is not a bad thing, but leads many to think the system has a leak or the engine is overheating.
The throttle issue is more than likely caused by slop in the linkages, causing the engine to surge. With the engine off, check the play in the linkages from the governor to the carb. All it takes is a little play to cause things to act up. Most of the time it is the governor rockshaft that has a bit of play in it. As you move the shaft back and forth, look for play where it enters the governor, and also at the pivot itself. Check the carb throttle shaft plate to make sure it has not come loose from the shaft.

[JayIH]

Hi Raymond,
Thanks for the input. I had a feeling there might not be a water pump, but I had never encountered a system without one, so I thought I just wasn't seeing it.

The throttle only happens when it gets warm. I'm not sure what specific parts you are refering to, as I don't know the technical names, so I'm going to guess.

At full throttle when it gets warm, it will ease off the fuel to idle, and back up, in rapid succession, until it dies. I have no idea what is causing this. The actual throttle on the panel doesn't move, however the rod connected to the carb will move, moving the rod that goes side to side across the engine, to where hte spring is. The only slop or play I can find is on the right side where the rod that goes across the engine connects to the slide cable that leads up to the dash, and it's very light. The throttle was moving more than that, as though whatever that rod goes into was backing off the throttle manually. It's hard to explain. I will attempt to take pictures and video tomorrow of the actual process and where I'm talking about.

[Eugene]

Engine surging - common sympton of fuel supply problem.

Suggest obtaining the operator's manual, a service manual, and a parts manual for the tractor. The operator's manual will provide all necessary information on general maintenance. The service manual and parts manual will provide indepth detail on how thing work and repaired.

Names for those thing-a-bobs and whatch-a-macall-its are contained in the above reference.

[JayIH]

I've found plenty of info on the Farmall Lo-Boy, but I can hardly find anything on the IH Lo-Boy. I have a parts catelog, it's almost an inch thick, and it says it covers the IH, but there's virtually no information in it in the book. I have had trouble locating a shop manual for it, if anyone has a link to one that would be great.

[RaymondDurban]

Jay, all the lowboys were International Lowboys, even before the numbered series.

For manuals click the link above. Here are some shortcuts:
http://www.cleancomputes.com/Cub/Number ... index.html
http://www.cleancomputes.com/Cub/I&T%20 ... index.html
http://www.cleancomputes.com/Cub/Blue%2 ... index.html

[JayIH]

Thanks, that explains a ton!

I no longer have a sediment bowl. The previous owner must have replaced it with an in-line fuel filter, because that's what's there now. 90 octane reccomended? Wow. I'll sift through all that and see what I find.

[BigBill]

I run high test in all my power equipment as advised by my buddy who owns a lawn/garden - husky chainsaw shop. I notice a big difference in my car (subie) when i run regular and high test gas when getting on the highway. I have to push the gas pedal more with regular thus i burn more gas when going up the ramp. Its not a noticable difference in all cars. My int154's seen to run smoother with high test gas.

You could have some moisture in the fuel filter were with the fuel bowel you could see it in the glass. You could drain the fuel filter and add some dry gas to the gas tank if you see water in the gas from the filter. Then i would add some seafoam to the gas and crankcase oil and it should run great after a few times of use. About halfway to a tank of gas there has to be a noticable difference in performance and the idle.