PT 425 Kohler 25 HP Engine

[Spanky100]

Questions on the 25 HP Kohler Gasoline Engine used on the PT 425.

- is that an air cooled V twin horizontal crankshaft (730 cc) with single carb? (my guess from picture and limited description on PT Website)

- Kohler model number?

- how many hours would you expect with that engine before reduced compression/power/high oil consumption/hard starting would drive you to a rebuild or replacement engine? (I know time can factor in so lets think 100 hours per year with maintenance as called out in manual)

- What is the expected fuel burn in Gallons Per Hour for moderate to heavy grass cutting with 60 inch finish mower and grades 5 to 10 degrees (8 to 18 percent slope)

- is the engine lubrication the limiting factor for PT 425 slope capability or does the tractor stability limit out first?

learning more about the different PT Models

Thanks

Wayne

 

[Lnk]

After spending the last 4-5 years reading this forum, I think 1500-2000 hours is a safe range. So at the 100/year rate you are looking at 15-20 years. My limited experience with the robin 25 HP engine seems like around 1 gallon per hour. So you are looking at using between $4200-$6000 dollars worth of fuel at an average price of $2.50-$3.00/ gallon. A new engine seems like $1500-2000. Some of us spend more on the non-ethanol gasoline, so the numbers would be higher. That said, most contractors charge $75+ per hour for site work machine time.

I personally think these engines if well taken care of can last even longer, perhaps with less power as it ages.

Hope that helps.

Lnk

 

[MossRoad]

I do not know the model of the current Kohler engine that PT is reportedly using.

I have a CH25 in my 2001 model year PT425. It has about 1000 hours on it, so about 50 per year.

Issues I have had with this engine are:

- the mechanical fuel pump died (hole in diaphragm). I replaced it with a sub $20 vacuum pump.
- the valve rocker nut on one side came loose at around 950 hours, which caused a push rod to pop out from under the rocker. I could see it through the oil filler cap. When going to remove the valve cover, one of the valve cover bolts snapped off in the head with very minor pressure from me. I was able to just replace the push rod in it's place and torque the nut back down (no valve adjustment needed as it's hydraulic lifters), however, the bolt is still broken in there, which makes for a poor gasket seal, causing a slight oil leak, which makes a fire hazard.

Then several hours later, the other side did the same thing with the rocker bolt, only that time the push rod came up and poked a hole in the valve cover. Again, when going to remove the valve cover, another valve cover bolt broke the same way. So now I have two leaky valve covers.

I am still working on getting the bolts out without destroying the heads. New heads come to about $500 + valve covers, as the old covers don't fit new heads.

- on the old PT425 design, it uses the stock Kohler muffler, and that has to be removed to get to the battery. Guess what? Removing the exhaust stud nut, a stud broke off. I was able to extract that. So I took the opportunity to replace all of the exhaust studs. Don't think the battery under the muffler is a problem on the newer models.

- I've replaced 1 starter that died, and one starter that I mistook as dead, but later found I had the PTO switch on so it wouldn't start so I have a spare starter.

Other than that, I've had no engine problems.

Mine has a 5 gallon plastic fuel tank that leaks around the cap if I put more than 4 gallons in it. I can run about 4 hours on that 4 gallons, so about 1 gallon per hour mowing with the 60" mower or 48" brush cutter at full throttle. I'd say about 1.1 gallons per hour.

From my Kohler engine manual, the engine is limited to 25 degrees of continuous operation due to the lubrication system.

It's a pretty stable little machine. I do not know what the actual tipping angle of it is on a side slope. I try and take mine up and down. I have a couple 20 degree side slopes and that's not comfortable. Glad I have the arm rests.

You'd want to call Terry at PowerTrac to get the current specifics from them. They are very friendly and helpful.

 

[Goose1776]

I just bought a new 425
I’ll try to take pics of engine model number tomorrow
But I do know the machine is slope limited due to engine, not the machine. I asked about that specifically when I was there.
I will say, that the machine is capable of slopes that are uncomfortable for me. Lol

 

[Goose1776]

Pics of current engine model number,
Looks to be 730 model number
and layout.
I haven’t mowed enough to know the gallons per hour, but have heard others say gallon per hour, and that seems reasonable to me
I do know, at 1/2- 3/4 throttle just using the grapple moving brush, using the forks to move stuff around, etc. it sips fuel.

 

[Spanky100]

After spending the last 4-5 years reading this forum, I think 1500-2000 hours is a safe range. So at the 100/year rate you are looking at 15-20 years. My limited experience with the robin 25 HP engine seems like around 1 gallon per hour. So you are looking at using between $4200-$6000 dollars worth of fuel at an average price of $2.50-$3.00/ gallon. A new engine seems like $1500-2000. Some of us spend more on the non-ethanol gasoline, so the numbers would be higher. That said, most contractors charge $75+ per hour for site work machine time.

I personally think these engines if well taken care of can last even longer, perhaps with less power as it ages.

Hope that helps.

Lnk

Lnk

Great information. It is a significant help. Thanks

 

[Spanky100]

I do not know the model of the current Kohler engine that PT is reportedly using.

I have a CH25 in my 2001 model year PT425. It has about 1000 hours on it, so about 50 per year.

Issues I have had with this engine are:

- the mechanical fuel pump died (hole in diaphragm). I replaced it with a sub $20 vacuum pump.
- the valve rocker nut on one side came loose at around 950 hours, which caused a push rod to pop out from under the rocker. I could see it through the oil filler cap. When going to remove the valve cover, one of the valve cover bolts snapped off in the head with very minor pressure from me. I was able to just replace the push rod in it's place and torque the nut back down (no valve adjustment needed as it's hydraulic lifters), however, the bolt is still broken in there, which makes for a poor gasket seal, causing a slight oil leak, which makes a fire hazard.

Then several hours later, the other side did the same thing with the rocker bolt, only that time the push rod came up and poked a hole in the valve cover. Again, when going to remove the valve cover, another valve cover bolt broke the same way. So now I have two leaky valve covers.

I am still working on getting the bolts out without destroying the heads. New heads come to about $500 + valve covers, as the old covers don't fit new heads.

- on the old PT425 design, it uses the stock Kohler muffler, and that has to be removed to get to the battery. Guess what? Removing the exhaust stud nut, a stud broke off. I was able to extract that. So I took the opportunity to replace all of the exhaust studs. Don't think the battery under the muffler is a problem on the newer models.

- I've replaced 1 starter that died, and one starter that I mistook as dead, but later found I had the PTO switch on so it wouldn't start so I have a spare starter.

Other than that, I've had no engine problems.

Mine has a 5 gallon plastic fuel tank that leaks around the cap if I put more than 4 gallons in it. I can run about 4 hours on that 4 gallons, so about 1 gallon per hour mowing with the 60" mower or 48" brush cutter at full throttle. I'd say about 1.1 gallons per hour.

From my Kohler engine manual, the engine is limited to 25 degrees of continuous operation due to the lubrication system.

It's a pretty stable little machine. I do not know what the actual tipping angle of it is on a side slope. I try and take mine up and down. I have a couple 20 degree side slopes and that's not comfortable. Glad I have the arm rests.

You'd want to call Terry at PowerTrac to get the current specifics from them. They are very friendly and helpful.

Moss Road

Great detail and information from a 20 year PT425 owner and operator. I hope to call Terry and get to PowerTrac this fall. Appreciate your information and know if I get a PowerTrac this group and PT are always willing to help.

Thanks

 

[Spanky100]

I just bought a new 425
I’ll try to take pics of engine model number tomorrow
But I do know the machine is slope limited due to engine, not the machine. I asked about that specifically when I was there.
I will say, that the machine is capable of slopes that are uncomfortable for me. Lol

Goose
Appreciate the information and nice to see a new purchaser make the PT 425 choice. I have been looking at a Ventrac 4500 for a few years to mow fields that have some slope sections that are beyond my comfort level on a traditional tractor with 3 point rotary cutter.

This PowerTrac site has caught my interest and expanded my search to PowerTrac equipment. I think the PT design Front End loader is an advantage over Ventrac 4500.

Thanks

 

[Spanky100]

View attachment 708317
View attachment 708319
Pics of current engine model number,
Looks to be 730 model number
and layout.
I haven’t mowed enough to know the gallons per hour, but have heard others say gallon per hour, and that seems reasonable to me
I do know, at 1/2- 3/4 throttle just using the grapple moving brush, using the forks to move stuff around, etc. it sips fuel.

Goose

Thanks for the great pictures. Nice to see the plastic fuel tank that Moss spoke of has ben replaced with what looks like and aluminum fabricated tank with a nice cap.

 

[TractorGuy]

I wonder why they don't just use a less expensive, more reliable, Briggs & Stratton engine.

Briggs & Stratton 44S977-0015-G1 25 HP Professional Series Engine

This genuine 724cc Briggs & Stratton twin cylinder engine offers dependable power for your equipment needs. With a power rating of 25 horsepower, this engine features a premium Dual Clean air filtration system, electric starter, and maintenance-free Magnetron electronic ignition. With a...

shop.briggsandstratton.com

 

[MossRoad]

Moss Road

Great detail and information from a 20 year PT425 owner and operator. I hope to call Terry and get to PowerTrac this fall. Appreciate your information and know if I get a PowerTrac this group and PT are always willing to help.

Thanks

You are welcome.

My only advice would be to make sure you sit on a few and put them through their paces and talk to a lot of owners. Also, realize that you can't take it down to the dealer easily, so you either have to work on it yourself, of find someone that will.

 

[MossRoad]

I wonder why they don't just use a less expensive, more reliable, Briggs & Stratton engine.

Briggs & Stratton 44S977-0015-G1 25 HP Professional Series Engine

This genuine 724cc Briggs & Stratton twin cylinder engine offers dependable power for your equipment needs. With a power rating of 25 horsepower, this engine features a premium Dual Clean air filtration system, electric starter, and maintenance-free Magnetron electronic ignition. With a...

shop.briggsandstratton.com

That's a vertical shaft engine. Do they make it in horizontal?

 

[Goose1776]

Goose
Appreciate the information and nice to see a new purchaser make the PT 425 choice. I have been looking at a Ventrac 4500 for a few years to mow fields that have some slope sections that are beyond my comfort level on a traditional tractor with 3 point rotary cutter.

This PowerTrac site has caught my interest and expanded my search to PowerTrac equipment. I think the PT design Front End loader is an advantage over Ventrac 4500.

Thanks

I also bought a 1430.
I will admit to being a bit enamored with the PowerTrac platform.
Like Moss said, be sure you go sit on a couple and operate them.
The 1430 is much larger than the 425, and seems to have considerably more torque, but is less maneuverable in tight places.
The value of a PowerTrac is its versatility, it’s not the greatest for everything,
but it does a bit of everything better than anything else I’ve owned. If that makes sense. LoL
I’ve used the 425 every day since I brought it home.
It just works well for so many things
Including, stopping mowing the yard and doing
the very sad duty of pushing my beloved 2001 Chevy Tahoe down the drive, that my son wrecked this morning. ):
(He is only 17, and ok,)

 

[TractorGuy]

That's a vertical shaft engine. Do they make it in horizontal?

That came up under a horizontal search so I didn't realize it wasn't. They ARE showing a bunch of horizontal listings as "out of stock".

SOO I'm not sure if they make a good 25 HP horizontal that is available now.

I just suggested Briggs and Stratton because I have had excellent service out of that brand and seen plenty of issues reported with Kohler engines.

 

[MossRoad]

On my 2001 model year PT425, Kohler Command CH25, I have the two gear pumps mounted to the engine shaft.

On the other side of the engine, the screen has been removed and an auxiliary stub shaft is mounted the flywheel. That drives the variable volume pump.

So I'd need a replacement engine to be able to do that.

Looks like this:

 

[Spanky100]

You are welcome.

My only advice would be to make sure you sit on a few and put them through their paces and talk to a lot of owners. Also, realize that you can't take it down to the dealer easily, so you either have to work on it yourself, of find someone that will.

MossRoad

Great advice that I will follow with one concern. When I set on the PT1850, which is what I WANT but do not NEED, I will likely start to rationalize the PT1850 purchase for my lovely wifes' next Birthday Present. She has been a great wife and has put up with me for years but I am not sure I should spend that much on her next present.

She reminds me that she has never driven her tractor or her ZTR Mower.

 

[oldnslo]

Some of the older Kohler Command CH and CV series motors had issues with head gaskets going bad and leaking oil either into the cylinder or externally. This is a nuisance time consuming repair but rest of the engine is bullet proof.

 

[Spanky100]

I also bought a 1430.
I will admit to being a bit enamored with the PowerTrac platform.
Like Moss said, be sure you go sit on a couple and operate them.
The 1430 is much larger than the 425, and seems to have considerably more torque, but is less maneuverable in tight places.
The value of a PowerTrac is its versatility, it’s not the greatest for everything,
but it does a bit of everything better than anything else I’ve owned. If that makes sense. LoL
I’ve used the 425 every day since I brought it home.
It just works well for so many things
Including, stopping mowing the yard and doing
the very sad duty of pushing my beloved 2001 Chevy Tahoe down the drive, that my son wrecked this morning. ):
(He is only 17, and ok,)

Goose

Glad your son is safe. He has received an early life learning lesson he will likely not forget at your loss of the Tahoe. Tahoe's will run forever with low cost parts until a major issue that is not worth repairing. I too have experienced that with my son. The phone to dad call was funny - Dad I am ok and think the truck is drivable if you can pull me out of the snow. Son had an optimistic view of damages after hitting glaze ice on a bridge overpass.

I want to use The PT for field mowing with some slope areas that are above my comfort level with a conventional tractor. Thinking the PowerTrac front end loader might be better than my conventional tractor front end loader work. I just have to get over what a tractor should look like

Thanks

 

[cqaigy2]

Goose
I just have to get over what a tractor should look like

Thanks

Ha ha, i know what you mean. I really wanted to NOT be impressed the the PT, but my wife talked me out of a conventional tractor platform. She'd not been brought up around farming and such, so had not preconceived ideas about tractors, she just looked at what we would be using the PT for. BTW i still think tractors are cool looking.

 

[MossRoad]

I agree. I'd much rather drive an old tractor in a parade than my PT425.