Bx2660 getting hot

Mountainman

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L2501, B7100, B6000, B21, B1750, B2400, B7200
Jul 10, 2022
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Attalla Alabama
mossycreekoutdoors.com
When I bought it all the screens and radiator was clogged up behind battery. Cleaned all that out changed oil all that stuff. First time I mowed with it it got close to the red on the meter. Found water pump had just a little bit of wobble to it so I replaced that and put a new thermostat in. Flushed the system and ran water through radiator while it had it out. Fins all look good on the radiator and not clogged up. New 50/50 antifreeze and new radiator cap. Now it'll mow for about 30 min at a reasonable spot on the meter then climb to the red. I used my temp gun and got 217 at the head where the sensor is and 182 on top radiator hose and 170 on bottom radiator hose. How much variance should there be between the top and bottom hose? Thinking maybe radiator is partially clogged inside or something. Any other ideas? Also no signs of boiling over or anything. No bubbles in the overflow. No bubbles in the radiator when running cold. Thank you
 

85Hokie

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I would say you have found your culprit !!!

Typically on a hard working engine - the water temps will get close to 220F - most cars/trucks/etc will run right at 210, not sure why that is magical but that is where most "normal temps" end up.

to answer your question - if close to 200F at top there should be more like <100F at the bottom. Again this is on an engine that is being worked hard, not at idle. SO there should be a least a 100 F drop across the radiator.

How many hours on this machine?

And you sure the water pump is doing the job? OEM pump or aftermarket?
 
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Mountainman

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L2501, B7100, B6000, B21, B1750, B2400, B7200
Jul 10, 2022
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Attalla Alabama
mossycreekoutdoors.com
I was thinking there should be more variance In top and bottom hose. When I filled it up I could see flow in the radiator but I haven't removed the top hose to see how much. It is an oem Kubota water pump.

With what you said now I'm curious if the temp sensor is working correctly also. If 210 at the head is a normal running temperature then I wouldn't think the meter should be right at the red line. It is just a dummy guage I know. I measured temp at the head when the guage was running just a little above half way and it was 190. But either way sounds like it's new radiator time
 

GreensvilleJay

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My gut is saying rad is 'kinda' plugged. Either take to a rad shop to have it cleaned or do it your slef. probably several 'cleaners' you can use. Neighbour used muriatic acid on a gas pool heater..amazing diference ! Someone here MUST know what 'chemical' to use.
It's not just being 'plugged' that hurts, it's the buildup of 'stuff' that acts as an insulator and not allowing the heat to get transferred.
 

cthomas

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LX2610 HSDC
Jan 1, 2017
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I have used muriatic acid on heater cores with a reverse flush afterwards. What is the radiator made of?
 

PoTreeBoy

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My gut is saying rad is 'kinda' plugged. Either take to a rad shop to have it cleaned or do it your slef. probably several 'cleaners' you can use. Neighbour used muriatic acid on a gas pool heater..amazing diference ! Someone here MUST know what 'chemical' to use.
It's not just being 'plugged' that hurts, it's the buildup of 'stuff' that acts as an insulator and not allowing the heat to get transferred.
I agree. If the water flow were low due to a bad water pump, the bottom temperature would be lower. I cut the old radiator from my 2003 Ford Explorer and you could see a thin buildup of what looked like dirt on the inside of the tubes. A new radiator fixed it. An aftermarket radiator for the Ford was pretty cheap, so I didn't fool around with trying to flush it.

Fleetgard Restore Plus might be worth a look.
 

Mark_BX25D

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Bx25D
Jul 19, 2020
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I have used muriatic acid on heater cores with a reverse flush afterwards. What is the radiator made of?
Plastic and aluminum.

That's a good combination. It makes aluminum chloride and hydrogen gas where your radiator used to be. :D


Regardless of the accuracy of the dash gauge, you have a (presumably) reliable reading of 180 and 170 on your radiator hoses. That says there's a problem. You are not cooling the water as much as you should. Either the system is clogged, reducing flow, or the pump is not doing its job.
 

Mountainman

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Attalla Alabama
mossycreekoutdoors.com
That's a good combination. It makes aluminum chloride and hydrogen gas where your radiator used to be. :D


Regardless of the accuracy of the dash gauge, you have a (presumably) reliable reading of 180 and 170 on your radiator hoses. That says there's a problem. You are not cooling the water as much as you should. Either the system is clogged, reducing flow, or the pump is not doing its job.
Agreed. Only thing that makes sense. Time for new radiator it is
 

cthomas

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LX2610 HSDC
Jan 1, 2017
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La Farge Wi
Yep, as a radiator shop can't boil it out(20 plus years ago I worked in one and made the mistake of trying to boil an aluminum radiator out, within 10 minutes came out with just 2 plastic ends(At least it was one of my projects). Did save the end caps and 2 years later needed one for customer that overtighten the worm clamp on the radiator(WOW). The company ended up getting out of the business due to all the environmental regulations. Can't remember what that the chemical was but it was nasty(even bought craftsman tools to work there as everything it that room was rusty with weeks(24 hour outside vent running).