B1750 - Overheating problem

bpowers135

New member

Equipment
B1750
May 10, 2013
3
0
0
summerfield,nc
I have a B1750 HST with 800 hours that overheats only when engine runs above 1900 RPM with and without screens in place.

To try and correct the issue, I have completed the following work.
1. Replaced the water pump.
2. Removed the thermostat.
3. Replaced the Fan Belt.
4. Removed/flushed and cleaned the radiator. Filled with muriatic acid, let sit
for 20 minutes then flushed with garden house passing 5-7 gallons of water/min from top out the bottom.

Problem first occurred last summer, was mowing when all of a sudden my flash indicators on the dash board lit up and stayed bright along with the three lights on the bottom of the instrument panel. Caught my attention
temp gauge was in the red very briefly.

I shut down the mower, cleaned the screen, started it back up and now can't exceed 1900 RPM, FLASHER lights stay lit and get brighter with the RPM as well as the Glow Plug light.

At this point I am thinking about getting the radiator re-cored and wondering if it's possible to have another block in my cooling system.

Any feedback and comments are welcomed.

Thanks
 

Wbk

New member
Feb 20, 2013
307
0
0
St Adolphe Manitoba Canada
I have a B1750 HST with 800 hours that overheats only when engine runs above 1900 RPM with and without screens in place.

To try and correct the issue, I have completed the following work.
1. Replaced the water pump.
2. Removed the thermostat.
3. Replaced the Fan Belt.
4. Removed/flushed and cleaned the radiator. Filled with muriatic acid, let sit
for 20 minutes then flushed with garden house passing 5-7 gallons of water/min from top out the bottom.

Problem first occurred last summer, was mowing when all of a sudden my flash indicators on the dash board lit up and stayed bright along with the three lights on the bottom of the instrument panel. Caught my attention
temp gauge was in the red very briefly.

I shut down the mower, cleaned the screen, started it back up and now can't exceed 1900 RPM, FLASHER lights stay lit and get brighter with the RPM as well as the Glow Plug light.

At this point I am thinking about getting the radiator re-cored and wondering if it's possible to have another block in my cooling system.

Any feedback and comments are welcomed.

Thanks
Hi it appears that you have checked or replaced most of the important parts. Have you double checked the temp. with another gauge just to be sure of the exact temp. you mentioned you flushed the rad yourself, were the cores that you could see through the hole dirty? If the core is extremly dirty you might want to take it to a rad shop where they will remove the tanks to clean it and check to see if it has any blocked tubes. Hope this was of some help. Barry
 

dmanlyr

New member

Equipment
L3200, Hustler Super Z
May 30, 2012
330
1
0
Graham, WA
As mentioned, The first step is to determine if a problem actually exists by confirming the engine operating temp by a means other than the existing instrumentation.

Have you been loosing any coolant?

If a problem does in truth exist, then you have covered most of the basics. Although depending upon the system I will make a note that operating without a proper operating thermostat can induce a overheat where there is no mechanical failure other than the missing thermostat.

Next step would be to check for combustion gases in the cooling system from a leaky head gasket. They make simple test kits for this. Check out your local auto parts store such as NAPA.

Another thought is that you might end up re-coring the radiator as it is hard to inspect all of the tubes for blockages without a disassembly.

Please post what you find.

David
 
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bpowers135

New member

Equipment
B1750
May 10, 2013
3
0
0
summerfield,nc
Thanks for the suggestions. I will verify the temp via another gauge and look into the possibility of exhaust gases in the cooling system. I should mention a few other items. I have run with and without a new thermostat, no change and have replaced the radiator cap with a new one. I have also ran a couple batches of radiator flush mix... goes in clear comes out dirty and blackish.
There are no leaks from what I can see.

Also when I back the RPM's off to under 1900 the temp slides right back down into the normal zone just as fast as it rises. ( using dashboard gauge).
My first hunch is it's a flow issue and I am not moving enough coolant through the engine at higher RPM. As for the head gasket, that might be an issue, however I can run all day long at 1900 RPM with a load with no overheating.

The last ten years I have been running the tractor at a pretty good clip,
without any issues, except replacing the glow plugs. My front yard is 2 1/2 - 3 Acres and it usually only take me 40 minutes. It's now taking me about 75
minutes at a slower clip.
 

SteveF

New member

Equipment
BX25
May 15, 2013
307
0
0
Huntingdon, PA
All good advice above.

First step is to confirm or refute that the coolant temperature is actually elevated.

Did it boil over or steam out the radiator cap?

Have you checked the temp sensor?
 

Wisconsin Tom

New member

Equipment
B2400
Apr 3, 2012
5
0
0
Menomonie, WI
My coolant is definitely overheating. Winter is fine but heavy mowing in the summer gets it every time. The temp gauge rises and rises and eventually it will steam and boil. I've replaced the thermostat, but that's about it. I just turn it off, let it cool down and add coolant. Head gasket?
 

SteveF

New member

Equipment
BX25
May 15, 2013
307
0
0
Huntingdon, PA
My coolant is definitely overheating. Winter is fine but heavy mowing in the summer gets it every time. The temp gauge rises and rises and eventually it will steam and boil. I've replaced the thermostat, but that's about it. I just turn it off, let it cool down and add coolant. Head gasket?
With the additional info it is starting to sound like an obstruction in the system (or obstructions in the core) if it runs at acceptable temp in the winter, etc. Your flow diagnosis make sense.

Are you having to top off the radiator frequently and if so what do you use to top off? Full strength coolant, mix, etc. Have you mixed different coolant types over the years... that can corrupt the system.

How are you flushing? Garden hose? That gets the loose debris out of the radiator, but a pressurized system is much more effective and gets to the entire system.

Not really sounding like a head gasket if you're not loosing coolant or seeing a change in exhaust color.

Are you burning engine oil?
 

Wisconsin Tom

New member

Equipment
B2400
Apr 3, 2012
5
0
0
Menomonie, WI
With the additional info it is starting to sound like an obstruction in the system (or obstructions in the core) if it runs at acceptable temp in the winter, etc. Your flow diagnosis make sense.

Are you having to top off the radiator frequently and if so what do you use to top off? Full strength coolant, mix, etc. Have you mixed different coolant types over the years... that can corrupt the system.

How are you flushing? Garden hose? That gets the loose debris out of the radiator, but a pressurized system is much more effective and gets to the entire system.

Not really sounding like a head gasket if you're not loosing coolant or seeing a change in exhaust color.

Are you burning engine oil?
I've added coolant so many times that it's hard to remember. I think i've only used green (different brands though)...usually a 50/50 mix...but I have added it straight. I usually have to add coolant every time I mow because it inevitably boils.

It doesn't burn/use much (if any) oil and I've only flushed t with a garden hose.

What should I be looking for in the exhaust color?
 

bpowers135

New member

Equipment
B1750
May 10, 2013
3
0
0
summerfield,nc
Found a resolution. The Temp Gauge was acting up because the ground wire under the seat had broken off. The gauge was using the glow plugs as a ground which caused the glow plug indicator to stay lit and brighten with the additional RPM's as well as the temp indicator to shoot up. Fixed the broken ground wire working as good as new.
 

Daren Todd

Well-known member
Lifetime Member

Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
May 18, 2014
8,964
4,330
113
Vilonia, Arkansas
I've added coolant so many times that it's hard to remember. I think i've only used green (different brands though)...usually a 50/50 mix...but I have added it straight. I usually have to add coolant every time I mow because it inevitably boils.

It doesn't burn/use much (if any) oil and I've only flushed t with a garden hose.

What should I be looking for in the exhaust color?
Start it up, and remove radiater cap. If you see bubbles, then chance are good that you have a blown head gasket.
 

Rob L

New member

Equipment
B1750 HST
Apr 20, 2017
1
0
0
Glen Rock PA
I've added coolant so many times that it's hard to remember. I think i've only used green (different brands though)...usually a 50/50 mix...but I have added it straight. I usually have to add coolant every time I mow because it inevitably boils.

It doesn't burn/use much (if any) oil and I've only flushed t with a garden hose.

What should I be looking for in the exhaust color?


What did you learn I am having the same problem. Was it the head gasket?