PTO Speed

[tw4929]

I have a B-7300 with a small bush hog. When cutting grass, the RPM's are at max in the 540 rpm position which causes the engine to run very hot, almost pegged to red. Is is possible, or recommended, to use the 2500 rpm selection with a lower engine rpm? After about an hour mowing, this little engine is boiling hot.
Thanks for your help,

 

[RMS]

Not sure about the RPM's, but are you checking and cleaning the radiator while brush hogging? The radiators seem to clog up more during brush hogging than any other time for me. There are plenty of posts here on overheating due to clogged radiator fins and the damage that can occur.

 

[GrumpyFarmer]

I would think that machine should run all day with no issues, so long as engine room in good shape and not too much dirt/debris on the radiator fins, and fresh coolant.

when was the last full service last completed?

 

[Russell King]

Changing the PTO speed range and running the engine slower will probably make the engine work harder and overheat faster due to changing the place on the power curve of the engine that it is operating at.

 

[TheOldHokie]

I have a B-7300 with a small bush hog. When cutting grass, the RPM's are at max in the 540 rpm position which causes the engine to run very hot, almost pegged to red. Is is possible, or recommended, to use the 2500 rpm selection with a lower engine rpm? After about an hour mowing, this little engine is boiling hot.
Thanks for your help,

Thst is not a solution for multiple reasons. You have a cooling system problem. Fix it and your tractor wiill mow all day at rated engine speed.

Dan

 

[John D 2]

Before I used it again, I would be inspecting the cooling system for issues.

 

[John T]

Not sure about the RPM's, but are you checking and cleaning the radiator while brush hogging? The radiators seem to clog up more during brush hogging than any other time for me. There are plenty of posts here on overheating due to clogged radiator fins and the damage that can occur.

I agree.

I blow out the radiator screen every time I cut the grass with my BX

It always has clippings and dust in it. Air intake filter as well.

only take a few seconds with an air hose.

 

[Caden]

No, that's a bad solution for a problem that should never exist in the first place.

My rad when I got my tractor was so clogged with dirt that I had to remove it and soak it in a tub of water to loosen it all up from between the fins.

 

[Killer Bee]

I have a B-7300 with a small bush hog. When cutting grass, the RPM's are at max in the 540 rpm position which causes the engine to run very hot, almost pegged to red. Is is possible, or recommended, to use the 2500 rpm selection with a lower engine rpm? After about an hour mowing, this little engine is boiling hot.
Thanks for your help,

first off, if your rear pto is a two or more speed, they're probably in the output rpm neighborhood of 540/750/1000 at wot.

1500/2500 rpm at wot are more likely specs for mid pto (belly) or front if equipped.

the kind folks here can lead you to operators and maintenance manuals if you ask.

secondly, you should never run an implement over it's rated rpm, follow manufacturers specs. over speeding rotary equipment is not good.

as mentioned, running your machine at same or similar load at lower rpm is also not good. most diesel tractors are designed to run at governed speed or wot (wide open throttle) at rated loads.

also mentioned, what is machine condition, specifically cooling system? besides clearing mowing debris for good air flow through radiator, how are the belts, fan, water pump, thermostat, coolant, etc.?

a handheld digital infrared thermometer is a great tool for cooling system troubleshooting. starting with a cold machine, take appropriate readings from warmup to operating temp or above to help identify the culprit(s).

how long has the machine exibited these symptoms? overheated in the past? current symptoms started suddenly, gradually, after any repairs, maintenance, or other incident?

how many hours on the machine? has is it exhibited these symptoms in the past with other implements/attachments?

how many hours (estimated, most don't have meters) or age on the brush hog? does pto turn smooth and easily by hand? no binding, popping, squealing, grinding noises?

good luck figuring it out!

 

[North Idaho Wolfman]

540RPM is the rear PTO speed
2500RPM is the Mid PTO speed, you can't alter either one.

 

[tw4929]

Not sure about the RPM's, but are you checking and cleaning the radiator while brush hogging? The radiators seem to clog up more during brush hogging than any other time for me. There are plenty of posts here on overheating due to clogged radiator fins and the damage that can occur.

Thank you.

 

[tw4929]

first off, if your rear pto is a two or more speed, they're probably in the output rpm neighborhood of 540/750/1000 at wot.

1500/2500 rpm at wot are more likely specs for mid pto (belly) or front if equipped.

the kind folks here can lead you to operators and maintenance manuals if you ask.

secondly, you should never run an implement over it's rated rpm, follow manufacturers specs. over speeding rotary equipment is not good.

as mentioned, running your machine at same or similar load at lower rpm is also not good. most diesel tractors are designed to run at governed speed or wot (wide open throttle) at rated loads.

also mentioned, what is machine condition, specifically cooling system? besides clearing mowing debris for good air flow through radiator, how are the belts, fan, water pump, thermostat, coolant, etc.?

a handheld digital infrared thermometer is a great tool for cooling system troubleshooting. starting with a cold machine, take appropriate readings from warmup to operating temp or above to help identify the culprit(s).

how long has the machine exibited these symptoms? overheated in the past? current symptoms started suddenly, gradually, after any repairs, maintenance, or other incident?

how many hours on the machine? has is it exhibited these symptoms in the past with other implements/attachments?

how many hours (estimated, most don't have meters) or age on the brush hog? does pto turn smooth and easily by hand? no binding, popping, squealing, grinding noises?

good luck figuring it out!

Thanks for the tips. I bought the machine used, of course. I know the fan belt doesn't look great, but still in tack. As far as the coolant, it probable should be changed. Looks like I have a project ahead.