PT422 Engine shaking / sputtering

[bjustice]

I would vote for the fuel injected Robin--and would ask about a stronger starter. I read somewhere about a different starter for special hardstarting applications. Sorry, don't know where. I'll keep looking.

 

[ernemats]

On the Robin cold weather starting, I have a 422 with Robin engine for 11 years and almost 1,600 hours on it, still the original battery, new ignition coils in the last 2 years and spark plugs are the only engine related items I have had to replace. I have some difficulty starting it in real cold weather, (below 20 degrees) but it usually starts if I use a magnetic heater on the hydraulic oil tank overnight. It is kept in an unheated garage. A friend of mine bought Scargs 429 last year and I do not know how much trouble he has starting it in cold weather. Another fellow I know had a 422 which he put in the Robin 25 hp engine . He said it was easy but he did not notice much difference in power. He put in different wheel motors which improved the hill climbing ability a great deal.

 

[bjustice]

I have been thinking about the possibility of installing the EH72 Natural gas/Propane version in my PT2522 when the time comes. It is a bolt-in except for mounting the gas bottle. That should be solveable. Also note that assessories are avail remote oil filter, mufflers ect. 30 amp alt and the NG/LPG should solve the starting problem. A download is here:

Wisconsin Industrial Products, Inc. - Engines

 

[MossRoad]

Oh yeah... and I will definitely take pics and create a how-to thread/tutorial on the engine swap. I think there are many people on this forum who could handle a project like this, but don't want to take on the risk due to some unknowns. If it can be broken down while addressing the main concerns, it might empower others to dive in and upgrade/replace their PT engines. If/when I'm successful, I'd be happy to share my experience.

Here's another opinion question: Disregarding potential issues with fitment and/or cost, which would you prefer in your PT?

1. a liquid cooled, carbureted Kawasaki
2. an air cooled, fuel injected Robin
3. an air cooled, carbureted Kohler Command Pro

In all honesty, I think any of them would be fine in the summer. I can get any engine running in the summer. But when I really, really need that machine the most, on those absolutely terrible winter mornings when it is ZERO degrees, dark as heck, the wind is howling at 20+ MPH, it has been snowing all night and I need to get out of the driveway to get to work to cover for all of the other folks that didn't plan for bad weather situations...

I would choose the Kohler again in a heartbeat! I can count on it to get the job done. :thumbsup:

 

[KMA]

I would choose the Kohler again in a heartbeat! I can count on it to get the job done. :thumbsup:

Yeah, I'm leaning that way too (although my mind changes daily).

I think it is going to come down to a Kohler Command Pro 25hp and the Robin EH72 FI, but the Kohler is ahead by a nose.

Kohler Command Pro CH730
+ automatic compression release and electronic ignition
+ good reputation
+ wide array of accessories/parts easily available
- tighter fit
- difficult to interpret "spec numbers" and find best version
Kohler Engines: CH730: Command PRO: Product Detail: Engines

Robin EH72 Fuel Injection
+ Fuel injection
+ Same size block for drop-in fit
+ Easy to translate known PT spec number to FI model
- harder to service/understand?
- Potentially higher price
- Need to purchase new coupling for smaller shaft diameter
Subaru Robin - Features and Benefits

The price for the CH730 varies quite a bit depending on spec number... Here's a good price on one that might work, but I'll need to do some more researching before knowing for sure:
Kohler Engine Number PA-CH730-0038, 25.0 HP Model: CH730S-0038 Command Series - On sale with free shipping at Tulsa Engine Warehouse!

 

[3238dpw]

Why not the Kohler FI engine. I believe it is 28 horse. that would be my first pic for a new engine. I asked my local guy about the reliability of the FI on the Kohlers, and he said that since they came out with them he has only one FI issue. He also said that the engines last longer with FI, are easier to start and use less fuel. that sold me.:thumbsup:

 

[KMA]

Why not the Kohler FI engine. I believe it is 28 horse. that would be my first pic for a new engine. I asked my local guy about the reliability of the FI on the Kohlers, and he said that since they came out with them he has only one FI issue. He also said that the engines last longer with FI, are easier to start and use less fuel. that sold me.:thumbsup:

Oh yeah, that would definitely be a great choice... unfortunately I saw prices on those that are $600-$1200 more than the models I considered above. That's a pretty steep price for FI.

I'm already potentially spending about $300 to upgrade from the EH72 recommended by Terry, to either the EH72 FI or the CH730. Adding a minimum of $600 more gets me further and further away from my goal of spending as little as possible and still getting something I want.

Note: if I really wanted to stay cheap, I would try to get the current engine repaired first, but I'm not happy with it's performance. That being said, I will probably repair my EH65 if its cheap enough to do. I will then either sell it or use it for something else. Anyone know of a generator kit that would work with it, or maybe another good use?

 

[MossRoad]

,,,,,,

Note: if I really wanted to stay cheap, I would try to get the current engine repaired first, but I'm not happy with it's performance. That being said, I will probably repair my EH65 if its cheap enough to do. I will then either sell it or use it for something else. Anyone know of a generator kit that would work with it, or maybe another good use?

Log splitter engine.

 

[MossRoad]

The Kawasaki engines are highly touted on the landscaper and lawn maintenance forums for powering mowers. However, I don't see much info about them in winter time use. Does anyone know of them being used in snow removal equipment. Also, in my environment, a liquid cooled engine would require a highly armored radiator. I frequently get sticks and debris jammed into the steel grating in the PT425 engine compartment. That is one advantage an air cooled engine has over liquid cooled for my uses.

 

[KMA]

The Kawasaki engines are highly touted on the landscaper and lawn maintenance forums for powering mowers. However, I don't see much info about them in winter time use. Does anyone know of them being used in snow removal equipment. Also, in my environment, a liquid cooled engine would require a highly armored radiator. I frequently get sticks and debris jammed into the steel grating in the PT425 engine compartment. That is one advantage an air cooled engine has over liquid cooled for my uses.

Yeah, I'm 99% sure it will be air cooled at this point. I can't justify the additional cost and effort for potentially little-to-no real world benefit in my implementation. It was fun to think about though. :drool:

There's also a really good chance it will end up being the Kohler CH730 too. I believe it will fit (albeit tightly) and it has some features that should help with cold weather starting. Plus, as I mentioned earlier, there are a lot of nice accessories that are readily available. For example, there are parts that allow me to relocate the oil filter to an easy to reach location, and help me build the external muffler. I might be able to find similar items for other engines, but the Kohler stuff is everywhere. Plus the price is only a few hundred above the EH72.

 

[Gravy]

I will be really interested to see how the Kohler fits if you go that way. One of these days I will have to replace my Robin, and I'd like to have an alternate choice.

 

[Vacuous_One]

Well...if anyone cares, I've put the Robin Subaru FI injected engine (EH72) in my PT422.

The old engine just quit on the wife one day while she was mowing and wouldn't start again. Pulled it and played around with it awhile, but finally just got tired of it. Never liked that Robin engine...wouldn't start when moderately cool...like so many others have stated!

So, I looked for possible replacements and finally settled on another Robin engine. (Wasn't hoping for that because of all the hassles it gave me, but went with it due to the cost and lesser modifications needed to fit it in the tractor.) Also, I really wanted fuel injection. Never have had a lot of luck with carburetors, either. The only change I ended up having to make was to slot the engine mounting holes in the tub as I needed to shift the new engine to one side about a 1/4" for additional clearance to fit it best.

After running it for a bit now, I have to say we're quite satisfied. The bloody thing even starts easily now! And, it's much smoother running than that older, smaller engine.

I can't say we've noticed anything terribly different regarding operation...i.e., the HP difference isn't really evident...although, it might have helped when mowing and trying to go up some of the banks around the place. It's hard to judge though, might just be wishful thinking, although I really think it's helped at least a bit. Seems to go up the hills easier with the mower running whereas the older engine really required a big slowdown in forward motion!

Now that winter's here, we'll see how it really does, though! I'll try and post observations as the weather gets a bit colder.

 

[Gravy]

I care!

Thanks for the info. Cold starting has been the Number 1 issue with my Robin engine. Please update with how it starts in sub-freezing temperatures. If it starts without help at 20*F or lower I might have to start looking for one.

 

[duane]

You bet we care. Any pictures you could share. This is big for us PTers with robin engines.

 

[Marks481]

Details, please! Engine model and number. Shaft size? Did you need a new spider coupling to mount the pumps? Does your PT have all the pumps mounted on one side of your engine, or all on the same side? Muffler arrangement? Where did you buy it?

Pictures, please. If you look in the archives, debates of replacement engnes are one of the more popular topics.

Stories like this make me want to upgrade my PT, but (hopefully) my engine still has years and years of life. As much as I would like to emulate Tim Taylor and soup up my tractor...

I would love to have a few more hp... My 22 hp robin engne feels weak, starts to bog down when the grass gets tall when I am cutting.

 

[Vacuous_One]

26°F out...PT stored in unheated metal building...sitting unused for ~ 1 month...standard oil as from the factory...throttle at 1/2, crank for 5-10 seconds & started. No problem! :thumbsup:

After using for ~1 hour, left sit outside for ~2 hours...throttle at 1/2, crank for 2 seconds & started. :thumbsup:

The old engine wouldn't have started in the first place without multiple attempts, ether, or jumper cables. Heck, it wouldn't even do that at 50°F, let alone 26! :laughing:

Pic's attached: Overall views, engine, some details, etc.

As stated previously, had to slot the motor mounting holes to shift the engine to the right to provide clearance...see the spark plug wire on the "...Tub Clearance.jpg" photo曜ust enough room to keep it out of the way of the hood.

Also, (forgot) that I had to add a return line to the gas tank to accomodate the fuel injection. Again, pretty easy thing to do. Bought grommet and angle fitting for the hose connection, drilled hole for the grommet in the plastic tank, installed grommet and fitting, installed hose, done.

The oil dipstick just touches the muffler flange slightly, but not enough to worry about. (That's the engine muffler from the EH65 engine that was installed originally from the factory.) I'll get around to taking care of that when I've got time or an urge to do it.

Finally, I like the oil filter location/angle...it's slanted down and to the back. This makes it easier to remove and install. The old oil filter location (and the existing hydraulic filter) were my two biggest pet peeves about the layout of this machine. They just weren't/aren't user-friendly.

The engine cost $1944 and I paid $150 total freight. While a lot more than I could have spent getting the old engine fixed and more than I would have liked to have paid, I'd still do it again. In a minute. It's that much better with this engine. Time will tell as far as longevity/trouble, but for now we're quite happy. The machine's finally reliable and usable when the temperature drops below 50°!

I don't know how the latest carbureted Robin engines are, but I'd never buy another one. I'd negotiate with P/T to pay the difference and upgrade to the fuel injected engine on any new machine!

In any case, that's my humble opinion after all I've gone through...other opinions may vary...

 

[Vacuous_One]

Details, please!

Engine model and number. Robin Subaru 28HP FI, #EH722DSF010

Shaft size? 1 1/8" OD. Also had to cut it down to the correct length.

Did you need a new spider coupling to mount the pumps? Yes. But, only because the ones in place were deteriorated/broken. Replaced them with the same part. I needed a new coupling as well. I bought both from alternate, third-party sources.

Does your PT have all the pumps mounted on one side of your engine, or all on the same side? Opposite ends. Wheel drive on the front side (toward operator), steering to the rear.

Muffler arrangement? Reused the existing one originally installed on the original engine.

Where did you buy it? (Engine? I bought it through a distributor in New York as there was no dealer in my area. Distributor = Henry W. O'Neill Associates, Inc., 795 Canning Parkway, Victor, NY 14564 1-800-724-3144. Really nice people, quite helpful.

Pictures, please. If you look in the archives, debates of replacement engnes are one of the more popular topics.

Stories like this make me want to upgrade my PT, but (hopefully) my engine still has years and years of life. As much as I would like to emulate Tim Taylor and soup up my tractor...

I would love to have a few more hp... My 22 hp robin engne feels weak, starts to bog down when the grass gets tall when I am cutting.

Tim, I hear you...I've added my answers to your questions in blue in your quoted statement. (At least, I hope I did...hope it comes out the way I think it will when it makes it up on the site! If not, I'll give it another try...

 

[KMA]

Well...if anyone cares, I've put the Robin Subaru FI injected engine (EH72) in my PT422.

Thanks so much for posting this information! :thumbsup:

Your feedback definitely makes me feel more comfortable in choosing the EH72 FI as a replacement. I was so concerned about cold whether starting, I planned on buying a Kohler. But there's no denying it would be much, much easier to drop in another Robin engine. Based on your feedback, I'm pretty sure that is the route I'm going to go now. I've been traveling overseas quite a bit lately and have had no time to work on my tractor. I have some vacation time coming up after Xmas and will try to get started on the replacement then.

Only issue (albeit minor) is that the shaft on my EH65 is 1 7/16 vs 1 1/8 on the EH72 FI. I'd have to get a different coupler setup.

Thanks again!

 

[Vacuous_One]

KMA, glad to be of some help. Good luck on your upgrade!

 

[J_J]

Well, I guess you could really call your updated PT, a 428, since the HP is the last 2 numbers in the model number.