1998 520H Kohler 22 dying

[rmschaver 18]

Whats a good replacement for my kohler 22hp 665XX engine?

[ZXT 2,401]

2 minutes ago, rmschaver said:

Whats a good replacement for my kohler 22hp 665XX engine?

What makes you think it's dying? More info on what it is doing would be excellent.

 

If it actually is on its last legs, I'd say that rebuilding that engine, or finding a good used engine would be far easier than putting another engine in its place. 

 

 

[rmschaver 18]

running hot and losing oil from the head gaskets not much but consistent.  Don't mind rebuilding but I would like to get this thing reliable again and quick.  With 7 acres to deal with I will fall behind on lawn care and quick.  I picked this thing up used and it ran good for a couple years with the exception of the hottest months. After some investigation valve guides are a common issue for the Kohler causing hot running.  Symptoms are engine hot after an hour more or less and engine acts like it's starving for fuel.  Fuel filter is new, air filter is new, fuel lines are new... once hot and dying starts using choke helps but to a very minor degree.  I am thinking the hot running is causing vapor lock as the fuel line must run between the V for both cylinders???  Letting engine cool down allows another hour or so of run time. 

[ZXT 2,401]

8 minutes ago, rmschaver said:

running hot and losing oil from the head gaskets not much but consistent.  Don't mind rebuilding but I would like to get this thing reliable again and quick.  With 7 acres to deal with I will fall behind on lawn care and quick.  I picked this thing up used and it ran good for a couple years with the exception of the hottest months. After some investigation valve guides are a common issue for the Kohler causing hot running.  Symptoms are engine hot after an hour more or less and engine acts like it's starving for fuel.  Fuel filter is new, air filter is new, fuel lines are new... once hot and dying starts using choke helps but to a very minor degree.  I am thinking the hot running is causing vapor lock as the fuel line must run between the V for both cylinders???  Letting engine cool down allows another hour or so of run time. 

Have you ever pulled the tins off of the engine and cleaned the fins out?

[WVHillbilly520H 10,376]

Is it a 520xi with foot pedal motion control and 2 spd hydro? If so that engine needs to be pulled and tins removed periodically, the oil leak makes it worse as this attracts and holds debris like dust grass and chaffe. Those Kohler Command can still be had new for around $1200, but honestly it should only take you a weekend to pull, clean and repair that engine vs replacement JMO. (BTW the 520H is the classic no engine side shields with the opposed twin Onan). Here they are side by side on the left 520H right 520xi.

[Ed Kennell 41,976]

Before you scrap it, in addition to pulling the tins and cleaning the cooling fins, pull the muffler off. 

   I just fixed a K301 that had some of the same symptoms.   It ran hot, threw oil, and required choke at full throttle.

I found the muffler was clogged restricting the exhaust.     Just sayin.

[JoeM 8,345]

Making sure the foam seals on the engine compartment are in good shape and in place. They separate the cool intake air from the engine compartment and stop reticulation of the heated air. The same cooling air is drawn into the air cleaner through triangular holes in the base of the air cleaner. Making sure these passages are open may help the carb problem.

And of course using full synthetic oil helps cooling too.

One old trick for cooling was to remove your hood, but in this case the removable side panels may help get rid of some heat.

 

[rmschaver 18]

Thanks for the advice.  I would rather not drop 1200-ish on a new motor that I don't need.  Thanks for setting me straight on the H and XI models.  I really like the horse it cuts great and has made clearing the old property I have much easier.  A few hours of elbow grease is in order now. 

[ZXT 2,401]

1 hour ago, rmschaver said:

 I would rather not drop 1200-ish on a new motor that I don't need.

Neither would anyone else! A couple of hours of cleaning could likely save you a ton of money.

 

I'm not sure how mechanically inclined you are, but if you need help/pointers, feel free to ask! We'd be glad to help. 

[Chestnut 315]

I'm going to add one more reason to periodically clean out inside the tins and around the engine. One photo tells it all. The critters haul all kinds of grass, acorns, and other nesting materials into the tractors. When I blew everything out of the other tractors after this incident my mother in law had, I had to dodge all kinds of debris. It wasn't caused by a fuel leak, but grass and mouse nests. By the time the FD got there there wasn't anything to do but break out the hot dogs and marshmallows. Fortunately nobody got hurt, it didn't spread, and the insurance company covered it at full replacement cost minus deductible..

[rmschaver 18]

I tried the cleaning and it was terrible dirty, grass cuttings and dirt clogging some of the fins.  I believe the wrong muffler is on the 520 XI. Someone had cut part of the heat shield off to make room for the muffler exhaust out the side.  Muffler also looks as if it has over heated as the outer can has bubbled and is discolored.  Not sure what I am going to do at this point.  I am considering a CH750 as a replacement.  I will not scrap this beast as I detest the throw away mentality.  Even if I can buy another for close to that price I might do both and just keep the old engine and rebuild it for a project.

[WVHillbilly520H 10,376]

2 hours ago, rmschaver said:

I tried the cleaning and it was terrible dirty, grass cuttings and dirt clogging some of the fins.  I believe the wrong muffler is on the 520 XI. Someone had cut part of the heat shield off to make room for the muffler exhaust out the side.  Muffler also looks as if it has over heated as the outer can has bubbled and is discolored.  Not sure what I am going to do at this point.  I am considering a CH750 as a replacement.  I will not scrap this beast as I detest the throw away mentality.  Even if I can buy another for close to that price I might do both and just keep the old engine and rebuild it for a project.

 

 

IMO get you some Gunk engine degreaser  (Simple Green or Purple Power degreaser full strength) get that engine fired up running 15-20 minutes or longer then spray it down with the degreaser (even brake cleaner/oven cleaner) let set 10 minutes or so agitating with a brush or scraper to get the worst off then rinse whether with a garden hose sprayer or a pressure washer to get most of that crap off the engine. Those series Kohlers seem to have crank seal issues and while you're at it replace those as well as the valve cover gaskets will help relieve some of the crime issues... Once back together compressed air cleaning after (each) mowing will help greatly as well. The muffler I can't help you with maybe @shallowwatersailor can shed some light on whether that's factory or not but on the 520xi I had for a very short time the exhaust did exit out the right side engine shield/cover.

[Chestnut 315]

That's a pretty oily dirty mess. I checked on Jack's Small Engines at the parts list for a generic Kohler CH22-66507 and the replacement sheet metal looks like it's available and not too expensive. There are a couple of different muffler configurations listed but I don't know what that tractor came with. The mufflers are on the pricey side, anyway. All that said, it's your call whether to pull that engine, replace, and use it for another project or just clean it up, correct any oil leaks, correct the airflow issues, and see how it runs. The same website shows three different part numbers for mufflers that exit on the starter side. Not obvious what's different between them. It's possible that previous owner got the wrong one and decided to do some surgery to make it fit.

These air cooled engines an be sensitive to the airflow. The Onan used on the 520H (earlier than your tractor) even have a gasket to seal between the oil filter and metal shroud to make sure the rear cylinder had enough airflow. 

I'd be with WVhillbilly520H and try the clean up, correct oil leaks, and blow it off regularly before I jumped into major surgery. But that's me, I usually try the low cost, low work option first. I recently had to clean up a mess around an oil leak. Started out with a spray can of a water based degreaser (don't remember what brand and I'm not home to check) followed by a water rinse. It seemed to leave a slight residue so I followed up with a spray of brake cleaner, wiped down and let dry. Had a clean dry surface after the brake cleaner dried.

[rmschaver 18]

I replaced with a Kohler CH730.  It is 23.5 rated HP.  Some issues with the swap.  Both muffler and clutch bar mounted to front of the engine needed to be drilled and tapped.  Kohler made it easier as they were pilot drilled.  Engine has a mechanical drive fuel pump that has a solenoid so that has to get hooked up to the run circuit.  The biggest issue was the crank shat is 1.435 inches so that required a new clutch.  All in at 2300 and change.  Still waiting on clutch but there is a definitely difference in drive speed.  I am keeping the old motor to rebuild for well...just cause I like doing it.  Looking for a second 520xi or dxi.  Yes I could have but another for what I paid but like I said I like doing it and well I am not a throwing away kind of guy.  Or one that keeps what does not work.

[Tuneup 1,452]

Thanks so much for the follow-up!

[rmschaver 18]

Welcome, I know I can't be the only one with a xi and these things aren't exactly on the shelf any more but well worth keeping around. Just because it is not easy does not mean it's not worth doing.  Some of the best things in life are hard to do and well worth the effort.

[WVHillbilly520H 10,376]

14 minutes ago, rmschaver said:

 xi and these things aren't exactly on the shelf any more...

Fellow Virginian I do happen to know where a NOS 522xi is setting waiting to be put to work...