Moving from an 1845 to a 425

[marrt]

I bought a new 425 around 2001 and used it for a year or so before selling the tractor to my neighbor. It was a great little machine but I needed more power for the projects I was tackling then. I "upgraded" to an 1845 and haven't looked back.

However, I recently purchased some land that's heavily wooded. I need to build some pathways through the woods and do basic clean up. The 1845 is a bit large for what I need to do on this particular property. I don't need pathways 6 feet wide. Plus, with the mower, the 1845 is difficult to maneuver around trees compared to the nimble 425.

So, here's my question: What has changed since the Mossroad-vintage 425 that I purchased originally? I seem to remember something about larger wheel motors, more engine torque from the Robin. What else... any more lift height? Has moving the engine further back decreased the PT-Pucker at rated lift capacity?

Sorry for all the questions. To be frank, I often found myself wishing for more power with the the earlier 425. Has anyone with an older 425 driven the new one? If so, could you "tell the difference." On paper, the 425 should be perfect for my new use. However, I have some steep terrain and I'm really worried that it won't be up to the task.

 

[BobRip]

It has about 40% more wheel motor torque. I have a 422 and would love to have that extra torque.

 

[MossRoad]

Marrt,
I'd call Terry at Power Trac and ask for the differences in the wheel motors between the 2000 models and today's version. I have hills and I could use a bit more torque on them (mine being a 2001 model year). I know the current 425s are a bit longer than mine, and they have a higher lift height. That required them to change the front end configuration a bit. They no longer have a hydroback cable to control direction. They have a hydraulic valve for a treadle and it uses hydraulic pressure through hoses to move the direction control on the variable volume pump. There were some complaints about the sensitivity of that new treadle design. I think there was a spring kit offered to increase the resistance of the pedals. It may be standard now. There have been cold starting issues with the Robbin. However, if they have switched to the EFI version of the Robin that may no longer be an issue.

Its funny you mention 6' wide trails. With my brush hog being 4' wide, when I cut new trails, I tend to make my first pass off center to the right and make a second pass off center to the left for a 6' wide trail! Hahaha. But you are correct, its easier to maneuver a 4' implement around trees than a 6' implement. There are some 'fat man's folly' areas on my trails where its exactly 4' between trees that I don't wish to cut down, or bend the trail around.

As for steep terrain, my Kohler is rated for 25 degree slopes. That's due to the lubrication system. So check your steepest slopes for angle and see if the current PT engine is rated for those slopes. If you talk about slopes, a 45 degree slope is a 1-1 ratio. That's one foot up for every one foot forward. Its hard for a human to walk up a 45 degree slope, let alone a machine. A 22.5 degree slope is one foot up for every two feet forward. That's uncomfortable on a tractor. Straight up and down isn't too bad, but sideways across a slop like that will still give you unpleasant feelings and raise the pucker factor. I do not like going across 22.5 degree slopes on my PT425, but it does it no problem. The stability is there, but it will crab sideways down-slope if the hill has leaves, soft sand, wet grass, etc... its so uncomfortable, that I try to traverse them only on the up and down directions. My 2001 PT425 will go up a 22.5 degree slope on our sandy leafy slopes even when the hydraulic system is hot, but it won't run the implement and push at the same time. It loses guts and traction. If I raise the implement just an inch off the ground, that transfers weight to the front tires, and up the hill I'll go, but I usually have to power off the implement to do that on hot days. There's a video of that on about a 15-18 degree slope on my website. http://www.mossroad.com/PT425Videos/PT425_brushhoguphill.wmv
That video shows that I had to lift the brush hog to maintain traction. A 4" log that stalls the brush hog. A 'fat man's folly' that I had to squeeze trough. Completely un-safe one handed tractor operation while filming. And revenge on the 4" log on the return trip. Its got something for everyone! :laughing:
Also, I have turfs in sand covered with leaves, so take that traction issue for what its worth.

So, the newer model 425s with improved wheel motor torque (if that's the case) would be a great improvement. See what Power Trac factory has to say.

 

[SpringHollow]

Hi Moss, that is a very nice review. On the 1850, I never even think about the fact that I am on a 20 - 25° slope even with singles on. I routinely do u-turns with a full 1 yard bucket while driving on the sides of my creek ditch that slope 20° in 2 different directions. I have never braved anything over 30°. Whenever I drive any of our CUTs, I have to remember that even a small slope can be a big deal.

I believe the newer 425's lift high enough to load a pickup truck? Marrt, remember you will take a hit in the lifting weight capacity. My single biggest wish for my PT is that it would lift more.

Ken

 

[woodlandfarms]

Moss, how many acres do you have?

 

[MossRoad]

We live on a little over 1 acre. Completely flat. 1/2 grassy lawn. I keep it nice on the road side of the house. The rest is covered by house, driveway, two garages, swimming pool, large garden and a dozen fruit tree mini-orchard. About 9 miles away, where that video was shot, we have about 20 acres of varying degrees of slope. There's a 65' drop in elevation from high to low point. The soil type is predominantly Tyner (sandy loam) a, b, c and d slopes. There is about 4 acres of Adrian muck in the lowland by the creek. An abandoned railroad grade traverses the eastern edge of the property and their is an old wooden railroad bridge over the creek. It shaped like a kite, with a high ridge running from tip to tail down the center. That ridge has about 10 acres of about 10,000 trees. Someone planted locust on that 10 acres many years ago, however there are nice stands of sugar maple, mixed oaks, wild cherry and about 20 other species. We are slowly (and I mean s-l-o-w-l-y) cutting out the locust and improving the maple and oak stands. I have this crazy idea of making syrup when I retire. The left side of the kite was a 4 acre field that we had reforested around 1990 with alternating rows of white pines and mixed hardwoods. The pines grew fast and pyramid shaped which stresses the hardwoods, forcing them to grow straight and skinny. After 20 years the pines reach 40' and stop growing. The hardwoods poke out above them and start gaining girth. We're managing the hardwoods for veneer timber for my kids or their kids if that should ever happen. If not, they'll have a nice mature forest to play with. The right side of the kite was a 6 acre field that we let run wild. Looking back, I should not have let that happen as crummy cherries have popped up and shaded out the light. I'll be removing them until I'm dead! :laughing:

I use the PT425 to keep about a mile and a half of trails open for walking and I let our neighbor hunt the property. He gives me venison and watches out over the property. Good arrangement. I also use the PT425 to haul out those locust trees to a landing. I girdle the locusts three times about an inch deep a foot off of the ground and let them stand for a year. Then I go back and drop 40-50 of them on a Saturday. The next day I'll pull them out with the PT. They are usually about 60' long. The huge ones I have to cut into manageable lengths, but for the most part they are telephone pole sized. I use the forks to stack them up in a neat pile and then I go back every weekend, start at one end of the pile with the chainsaw and lop off 16" pieces, throw them on the car hauler trailer and take them home. It takes me about 7 days to get my 6 cords out of the woods and back to the house. Then it takes me another 2-3 days to split it and stack it at home.

When we first bought the property, I purchased an old IH2500b tractor loader with cab, a brush hog and a box blade. I used that to brush hog between the rows of planted trees and to cut in a 300' driveway through a ridge at the highway. Once that heavy work was done I downsized to the PT425 for maintaining the property. It is just perfect for our needs.

I also volunteered the PT at the church and little league many times, help friends and neighbors, etc.... I'd buy another one. :thumbsup:

 

[cqaigy2]

Moss, you have a real skill when it comes to writing and descriptions.

 

[MossRoad]

Thanks! I'm, 22. 5'6 with blonde hair, curvy...... oh wait a minute, wrong website. :laughing:

 

[Marks481]

There have been cold starting issues with the Robbin. However, if they have switched to the EFI version of the Robin that may no longer be an issue.

I don't believe they have. The Robin EFI is a 28 HP engine, not the 25 HP that they advertise on the tractor. As of about 3 years ago (when Clumber bought his) they were still selling it with the carburator engine.

Too bad, since the Robin 28 EFI is fit/form/function replacement for the 25HP. It has almost the same performance, they just spec'd the hp at 4000 rpm vs. 3600 rpm.

Although Power-Trac historically hasn't been interested in substitutions like tho, you might ask them if you can get the PT-425 with the upgraded engine (The 28 EFI costs $400 more than the 25).

When my Robin 22 engine dies (or sooner), I will replace it with the Robin 28 EFI.

Or maybe this bad boy...
http://www.subarupower.com/newsletter.aspx?n=100

Robin EH90 35 hp.... the extra 2.5" in length might be hard to find without welding an extension onto the tub. Bet this wouldn't bog down when brush hogging. Of course, this isn't EFI, which kind of defeats the purpose of the upgrade...

 

[Frank Sorbello]

I called Power Trac today, and asked if I could upgrade to an EFI Robin engine. Chrissy said that is not an option. I have read numerous posts on this forum about the problems with the Robin Subaru engines, especially when it comes to cold starting. You would think Power Trac would be actively looking for a better motor for these machines.

I know there is a big hydraulic load on these machines when it comes to starting in the cold. How come it is not an issue with the older machines that have Kohlers, or the few guys that put in the EFI 28 hp Robin or the 29 hp Kawasawki.

I talked to a man the other day who was buying a Steiner tractor. He said he looked into a Power Trac, but read a lot on this forum about all the issues with cold starting Robin engines. So he is actively buying either a Steiner or Ventrac.

At some point I am going to purchase a new 425. (sooner than later) just wish they would give you an option.

Frank

 

[KMA]

The EH72 EFI engine helps with cold weather starting... but doesn't cure it in my experience. It probably can start reliably around 15 degrees colder than the carbureted version, but from what I've read it still doesn't quite match what the older Kohlers could do.

 

[marrt]

Guys,

I haven't had a chance to call PT yet. Will try to find time tomorrow and will report back.

Tom

 

[marrt]

On a related topic...anyone know the largest size wheel motor that will fit in the standard PT motor mounts? I suspect the motor mount is sized for the specific motor and, therefore, any change will require the motor mount be adapted. However, this might not be too expensive. In the last 14 years of posts, I remember this topic or a related version being discussed many times but don't remember the results. Time to warm up the search engine I guess.

 

[Marks481]

At some point I am going to purchase a new 425. (sooner than later) just wish they would give you an option.

Buy the PT425 and a Robin 28 EFI ($1800). Swap it out and ebay the Robin 25. Would cost more than if you bought it set up that way.

KMA did it to his PT422, didn't sound too hard:

http://www.tractorbynet.com/forums/power-trac/202389-pt422-engine-swap-completed-pics.html

 

[Gravy]

Marrt,

I've Googled this. If the White Hydraulics website specs for the CE series and my measurements are to be trusted, there should just be room in the wheel motor boxes to substitute a 16.8 cu in/rev motor for the stock 14.2 cu in/rev motor. At worst, a little shimming may be required.

 

[Gravy]

Buy the PT425 and a Robin 28 EFI ($1800). Swap it out and ebay the Robin 25. Would cost more than if you bought it set up that way.

KMA did it to his PT422, didn't sound too hard:

http://www.tractorbynet.com/forums/power-trac/202389-pt422-engine-swap-completed-pics.html

I've Googled this too. If we can trust the Subaru Robin website power curves for the EH72 series, the EFI version makes nearly all of it's "extra" power simply by revving to 4000rpm instead of 3600. It actually makes less torque at 2500rpm than the carbureted version.

FWIW, I've been running my 2004 carbureted EH72D at 4000 RPM for at least the last 8 years since I realized that my engine warranty was thoroughly voided by the air filter failure that deposited at least 1/8" of dust in the intake manifold. The engine has made it over 1100 hours now without blowing up and pulls a good bit harder than it did at 3600 RPM. As far as I can tell, the EFI version probably starts better in cold conditions and may use a bit less fuel. I'm not sure there is a noticeable difference in power at 3600 RPM.

 

[MossRoad]

On a related topic...anyone know the largest size wheel motor that will fit in the standard PT motor mounts? I suspect the motor mount is sized for the specific motor and, therefore, any change will require the motor mount be adapted. However, this might not be too expensive. In the last 14 years of posts, I remember this topic or a related version being discussed many times but don't remember the results. Time to warm up the search engine I guess.

You ever read the posts by jd-beach? I believe he paid Power Trac to install larger wheel motors from a 1430 onto his 425. That cut the top speed way down, but he put large tires (for sand flotation) on it to bring the speed back up. Ingenious!

 

[MossRoad]

The Kohler lugs pretty hard at starting in cold, like 10 degrees or colder. It has to with all of the cold hydraulic oil in all of those pumps. Frankly, I'm amazed every time it starts in those cold conditions. I can hear it turning at what I would estimate to be maybe 50-60 RPM with the starter.... that cold metal on metal whump....... whump..... whuuuhmp about 10-15 times before a pop. It scary! But it starts most of the time.

 

[KMA]

I agree about the power curve of the EH72 vs EFI version... virtually the same is my guess. Of course, I was coming from the EH65 so I did noticed a slight increase. If PT would swap in the EFI at the factory for a nominal fee, I'd do that. If not, I don't know if it'd be worth the effort and cost to swap it immediately after purchase. At that point, I might look for something more "exotic" (e.g. diesel, or liquid cooled).

Moss, the Robin acts the same way in the scenario you've described... except the Kohler will turn over for whatever reason and the Robin won't.

 

[MossRoad]

I wonder what the voltage coming out of the coils on the Kohler VS the Robin are? And what spark plugs both are using? Don't have time to check that stuff for a few weeks myself, sorry.