B7510 Losing Power today while Bushogging

[PSDStu]

I have been bushogging with my tractor for about the last week each day for about 8 hours a day....up till today all was well.....

1. I noticed today that my tractor was losing power while I was bushogging. Whenever I would start to climb a slight hill the rpm would start to drop off a couple of hundred RPM like it was bogging down. The mower wasn't cutting anything to tall and when I raised the mower deck it didn't really make much difference in the RPM. It also didn't matter if I was in High or Low, or 4WD or 2WD.... the engine just didn't seem to be developing the right torque.....plenty of RPM.... just no Power. I understand how the HST tranny works and I wasn't mashing the pedal down which could cause the engine to bog down while climbing a hill. It just seemed to be bogging down.

2. I also noticed that my throttle lever would max out at 2400 RPM which is the RPM for 540 PTO speed. I've never had a need to run it any higher but thought I should get more RPM then 2400.

3. Engine started getting real hot.......close to MAX temp....will need to blow-out radiator to remove debris from hogging.

4. Differental Lock..... I used it couple of times today when one of the rear wheels would spin....when I would push the peddle I could feel it engage..... I tried to engage the differental lock a couple times this afternoon and nothing happened...... I didn't feel the peddle enage.....not sure if this could be the cause of the lose of power....maybe the diff is NOT unlocked.....how can I verify that it's unlocked?

5. I am going to replace the fuel filter tomm and see if that helps the power situation...... I just replaced it not to long ago....but will give it a shot.

Anyways...looking for some or your inputs of maybe something I can look at, or may have missed.

Thanks!

 

[RoyJackson]

Check your air filter too.

I'm thinking the engine lost power as it heated up, so I suggest you clean that grill, radiator and radiator screen (if the tractor has one) and check it every ½ hour or so.

 

[ronjhall]

You may want to check Rotary Cutter for oil or if something is caught in blades and shaft.

 

[PSDStu]

Thanks for the replys!

I looked at the mower yesterday and all was normal.

Plan to clean radiator and air cleaner this morning and see how things go.

 

[DmansPadge]

Hey PSDStu... if the differential lock was staying engaged you would know it. It would want to drive straight and not turn.

 

[PSDStu]

I went ahead and replaced the fuel filter, and air cleaner, and cleaned the radiator... (it was trashed).... and all is well! Temps are back to normal and power was normal as well!

The differential lock is working just fine.

Thanks for the assist!

 

[RoyJackson]

I went ahead and replaced the fuel filter, and air cleaner, and cleaned the radiator... (it was trashed).... and all is well! Temps are back to normal and power was normal as well!

The differential lock is working just fine.

Thanks for the assist!

Great news!!!!

I'm sure all folks who responded are very happy, and some learned something.

Just check that grill/radiator every so often when you're mowing. It's easier to clean with just a little build up.

 

[Rusty]

I suggest you clean that grill, radiator and radiator screen and check it every ½ hour or so.

Roy & Others - The front grille, radiator screen and radiator on my Kubota B7500 with MMM collects dust and debris quite quickly. It normally requires cleaning every 1/2 to 1 hour. The grille and screen are fairly easy to clean in the field, but what is a good way to clean the radiator in the field, without portable compressed air? My 5 gallon portable air tank does not last very long. Rusty

 

[RoyJackson]

Roy & Others - The front grille, radiator screen and radiator on my Kubota B7500 with MMM collects dust and debris quite quickly. It normally requires cleaning every 1/2 to 1 hour. The grille and screen are fairly easy to clean in the field, but what is a good way to clean the radiator in the field, without portable compressed air? My 5 gallon portable air tank does not last very long. Rusty

I keep a small stiff brush in my bib overalls. I just keep the outer grill cleaned.

However, my little Deeres (670 and 790) have never got hot even when pretty clogged...maybe I've just been lucky.

I've seen 12v air compressors (Harbor Freight?) but I've never used one.

Remember, if the engine gets hot...disengage the PTO and reduce RPM, but don't just shut it down.

 

[Rusty]

I keep a small stiff brush in my bib overalls. I just keep the outer grill cleaned.

However, my little Deeres (670 and 790) have never got hot even when pretty clogged...maybe I've just been lucky.

I've seen 12v air compressors (Harbor Freight?) but I've never used one.

Remember, if the engine gets hot...disengage the PTO and reduce RPM, but don't just shut it down.

Roy - Thanks for the feedback! Cleaning the radiator is my biggest problem. It accummulates really fine stuff and is not easy to access, especially when the engine area is hot. Cleaning the grille and radiator screen buys some time, but does not get me all the way back to normal temperature. My engine will go all the way up to the red zone if I don't watch it carefully. Next time I mow the pasture or meadow, I will take my portable air tank and air compressor out to the field on the carry-all.

 

[JerryG]

Rusty, here is something that might buy you some time. If you wrap some of that black fiberglass window screen around the front of the grill it will slow down the amount of fine partials that gets on the radiator. I have used it before and it has helped. All the home improvement places have it as well as Wal-Mart.

 

[Renob]

A leaf blower works great if you have one. I always used pick on the leaf blower crowd.......until I got one. Now I use it for everything.

 

[Roadkill95]

A leaf blower works well sometimes if you can get it in where you need it

 

[smoothie17]

I use my leaf blower to dry my truck & tractor after washing; a lot faster than hand drying!

 

[charlz]

Remember, if the engine gets hot...disengage the PTO and reduce RPM, but don't just shut it down.

Not to hijack the thread but....

This makes sense if you have an engine with a water pump... letting it run at reduced rpm's will keep water flowing and cool down the engine. What about a thermosiphon engine? Water should continue to flow through the radiator when the engine is off, right? You don't have the fan pulling air through the radiator but then you also don't have an engine running to produce more heat.

Just wondering
Charles

 

[RoyJackson]

Not to hijack the thread but....

This makes sense if you have an engine with a water pump... letting it run at reduced rpm's will keep water flowing and cool down the engine. What about a thermosiphon engine? Water should continue to flow through the radiator when the engine is off, right? You don't have the fan pulling air through the radiator but then you also don't have an engine running to produce more heat.

Just wondering
Charles

The idea is shutting the engine down (stopping circulation) results in a heat build up (heat isn't being pulled off the engine). This is a heat soak situation.
The heat build up can warp the head and do other damage.

As far as your B7100 with thermosyphon cooling...see what your manual says, or maybe one of the guys with an older Kubota can help. It would seem you would still get the heat soak.