Kohler Courage 19 ACR/Starting Problem finally solved

[BIG_EB]

I'm new - this is my first post. Just wanted to share this information as it took me a long time to fix this issue with my Toro mower.
Symptoms - nearly impossibly to start cold. Sluggish starter - slowing down (fighting a closed exhaust valve). I set up a car battery on a trickle charger that I would then hook jumper cables to my mower battery.

Anyway starting this mower kept getting worse. I would throw a tarp over the engine and even run a space heater thinking it was just not going to start if it was below about 70 degrees.

Finally I started finding out about the ACR system. I went through the valves, looked at the valve guide, set and reset the lash, figured out the little set screw that goes in the rocker nut was never installed from the factory. Didn't matter.

I pulled the flywheel and opened the engine compartment and finally found the problem.

The mechanism that activates the ACR feature was broken it two pieces. This is the "weight" that rotates a little shaft attached that lives in the exhaust cam gear. By 'in', I mean the flat part of this part sits on the top of the gear, it's round section passes through the gear, and the half round section extends down into a slot machined into the cam. This part adds an extra bump to the cam surface while the engine cranks. This leaves the exhaust valve open longer and provides the compression relief. Automatic Compression Relief - and this part is the key to the whole thing working right.

So I pulled gear and found only the top half of the part in-tact. The bottom of the part - the half-round section had broken off and was down in the bottom of the crank case. I found it with a couple of bamboo skewers after fishing around for a while.

The fix - less than ten bucks on ebay. I picked up a set of gaskets, the little set screws, a new exhaust gasket off another site.

Put everything back together and she started right up. It's rainy and cold today - there's no way this machine would have started on a day like today...

The fracture on the part looked like it started at the reduction in material - right where the half-round section starts. The fracture was brittle - it started as a crack and worked back and forth over time. This explains the gradual onset of the problem - maybe. Part of that theory doesn't make sense to me but the part did not fail suddenly. The fracture slowly progressed across the half round section. Once it broke, I don't see how the broken section could have stayed in the cam slot but maybe. If it managed to ride in there for a while it could explain why it would suddenly crank like normal sometimes - but only after the oil was warmed up. Still - I don't think this explains everything.

My mower - 8 year old Toro Z4200 purchased new at Home Dept - Courage 19 SV590. You can find the manuals on line in PDF form, the parts websites have excellent drawings. I found this solution by going in after it. I didn't know what I was going to find, and everything I read on-line pointed to fixes that didn't work in my case.

Hope this helps someone else with the same engine (or similar). I ran with this problem for several years until it finally got bad enough to keep the engine from starting except in rare moments.

 

[mechanic mark]

Good deal, pat yourself on the back. It's called compression release, that's why it's important to check engine valve adjustment, engine cold, per your engine manual relating to hours on engine.

 

[BIG_EB]

Hey Thanks - finding a broken ACR weight inside the engine wasn't exactly expected. I feel your sarcasm.

I read the manual. They say - "If ACR isn't working properly, the engine will be nearly impossible to start." They don't say, "You just bought a great looking mower with a flawed internal engine part. Take everything apart in your spare time and keep digging - and by the way the broken piece is going to be floating around in the bottom of your crank case."

Can you say recall? Anybody else familiar with a Kohler of this age and type not starting? Anybody else a little confused about how to fix it? Anybody else have experience taking off your valve cover 4 or 5 times, checking everything, putting it back together....and your still stuck with the same problem?

Maybe I'm new to this forum. I'm an Engineer with over 25 years of experience in heavy equipment design, weldments, manual writing, stress analysis, oil field, and so on. I managed an Engineering department for an automotive related product for several years. I used to work for Toro - not with mowers but another line they were into. I don't fix small engines everyday and I don't like spending thousands of dollars on a mower that ends up with a failed internal engine component.

Just trying to share this experience. Not looking for a F'ing pat on the back. Apologies if this information might hurt your interests in any way.

This fix isn't obvious to a guy trying to work on his mower on a weekend when his yard if full of leaves, the grass needs cut, and your mower won't start. The manual was about as helpful as the information I found on-line.

That's why I joined this forum and that's why I posted this information.

 

[bertsmobile1]

Firstly thank you for your post.
Member who post for little more than public good are few & far between.

However as a trained engineer you should be well aware of the nature of quality control, the cost of quality control and the margins engine makers are working on.
This part took 8 yeas to fully fail and it is not a common failure.
I agree with you 100%, quality of engines has gone downhill at a rate of knots.
This is oddly enough due to advances in engineering technology where good engineers can substantially lighten components to a point where their service life is only marginally longer than the design life of the engine which in the case of a vertical shaft mower engine is 10 years.
This is not a defence of Koher per say, I hate this sort of modern manufacturing philosophy but it is ultimatly the buying public's fault.
There is a strange ideal that I am worth more money each & every year while every thing I want must get cheaper each & every year.
As such he who make the cheapests goods prospers while those who make higher quality goods go broke.
On top of that their is no loyalty at the bottom end of the market, proof of this is Tecumseh who killed themselves to deliver the rock bottom priced, reasonable quality engines and prospered doing so,,,, until China started to supply cheaper engines than the could make thus Tecumseh got wiped off the face of the earth.
The obverse is Honda who only make high quality products and when the buying public deserted them for no other reason that they could buy substantially inferior mowers for less money , they abandoned the sector, first complete ride ons and currently commercial mower engines.
There is almost no one with complaints about Honda commercials but now you can not find one on any large mower.
Kawakasi took oover this sector by supplying almost equivalent quality engines, cheaper and now that they are firmly established in this sector are downgrading the quality so as to now make a profit on these engines and failures are becomming more & more prevalent.

One of my customers just got a replacement engine because the Kawakasi on his commercial Torro failed after 220 hours .
It was 11 months old & had been service 3 times in this period, once by the agent & twice by myself.
The single rocker mounting bolt failed which sheared off the cast lug that replaces the second mounting bolt, allowing the entire rocker assembly to rotate ultimately destroting the rocker, head & cam. A deliberate cheapening design, poorley executed .
The mechanic at the shop told him they had several of these failures repaired under warrantee and their was no investigation or any attempt to palm off responsibility .
They looked at the photos I sent them then booked the mower in for an engine replacement and the only comment I got back was they were unhappy with it being fitted with Stens oil filters & not Kawakasi oil filters ( the Stens comes from the same factory & is identical to the Kawakasi filter ).
I took this as a clear admission of guilt.

 

[BIG_EB]

Thanks - very familiar with these concepts - very well stated. They say 'small is becoming the new big'... Maybe we'll reach a tipping point and things will bounce back the other direction someday.

 

[bertsmobile1]

Thanks - very familiar with these concepts - very well stated. They say 'small is becoming the new big'... Maybe we'll reach a tipping point and things will bounce back the other direction someday.

It is a hope of mine as well but untill we stop teaching that greed is good and return shop to the syllabus so students can recognise & appreciate good quality, design & value, I rather fear it is a hopeless cause.
For near 20 years I was the main contact for the local BSA club and in that time not one single person rang to ask where can I get a better quality part.
All they wanted to know is where they could get the cheapest ones.

If people really want to prevent global warming ( if you believe it is real ) then the fastest way to do it is not to purchase disposable, temporay diverted land fill no matter how cheap it is.
The cost of making garbage is only marginally more than the cost of making lifetime quality and the transport / distribution costs are the same.
You can have it all, you just need to acquire it slowly.

 

[alabama pat]

Big Eb,

I just tinker with a few toys and try to help out a few neighbors with a few mechanical issues.
I just took in a Husqvarna mower with a Kohler 21 hp motor.The issue you are referring to fits this motor to a tee.
I at first thought it may be the starter motor that was binding,but that was not the answer.I did buy a new battery as the one that was in it was extremely weak.
The motor will hardly turn over and when it does it does so in a halting manner.
Just what did you have to remove to access the broken ACR ,and did you need to remove the motor from the mower frame?
I would like to know what I am getting into in this case prior to jumping in with both feet.
I am most likely only going to work on this mower one time,so I do not want to buy a manual.
Any information you can give me would be great,as I need all the help I can get from you or anyone else for that matter.
This mower is not very old, (7-8 ) years,and it only has less than 400 hours on it.

Patrick

 

[bertsmobile1]

It is a very well designed motor service wise, you can dissasemble it in the frame but you must remove the pressure in both the blade & transmission belts or the crank will pivot on the lower bearing.
I drop the deck belt then slip the transmission belt off the rear pulley.
In theory simply locking the clutch/brake pedal down will do the same job but I always manage to trip it when working around the engine.

Most of the time it is simply wear in the valve train opening up the valve clearances which does not allow the ACR to work properly and /or the exhaust gasses to escape.

The big trouble came when the engine was made cheaper by replacing the light forged crank with a much heavier cast crank.

 

[BIG_EB]

Alabama Pat - I took off the flywheel with a puller. Took off the coil. Removed all the hex screws that hold down the engine case cover. It comes up with a little work. Take your time - everything is aluminum so don't force anything. I had to move the throttle linkage out of the way. Inside you'll see the crank and the top of the two cam shaft gears. The one on the left side, if seated on the mower, is the exhaust side cam gear and shaft. The ACR weight should be visable - the top of it at least on the exhaust cam-gear. The gear pull up and off the shaft. Before you remove it look for the timing marks. If you rotate the crank (put the hex screw back in and turn it with a wrench) you'll see both cam-gear marks line up on the crank gear at the same time. Then you lift out the cam-gear. Fish for the broken half of your ACR weight, install the new one, make sure the spring goes around the shaft of the ACR weight and it should hold the half round section out so it makes an extra bump on the cam surface. Then carefully put everything back together.

Kohler has manuals on their website you can download for free. It's helpful. I couldn't have done this repair without it.

If the ACR weight is OK, the problem might be the spring retainer, the spring, or a worn-off feature on the cam-gear that helps make the whole thing work right.

I did a valve lash adjustment after putting everything back together.

Replaced all my gaskets too.

Good luck!

 

[Srtech777]

I'm new - this is my first post. Just wanted to share this information as it took me a long time to fix this issue with my Toro mower.
Symptoms - nearly impossibly to start cold. Sluggish starter - slowing down (fighting a closed exhaust valve). I set up a car battery on a trickle charger that I would then hook jumper cables to my mower battery.

Anyway starting this mower kept getting worse. I would throw a tarp over the engine and even run a space heater thinking it was just not going to start if it was below about 70 degrees.

Finally I started finding out about the ACR system. I went through the valves, looked at the valve guide, set and reset the lash, figured out the little set screw that goes in the rocker nut was never installed from the factory. Didn't matter.

I pulled the flywheel and opened the engine compartment and finally found the problem.

The mechanism that activates the ACR feature was broken it two pieces. This is the "weight" that rotates a little shaft attached that lives in the exhaust cam gear. By 'in', I mean the flat part of this part sits on the top of the gear, it's round section passes through the gear, and the half round section extends down into a slot machined into the cam. This part adds an extra bump to the cam surface while the engine cranks. This leaves the exhaust valve open longer and provides the compression relief. Automatic Compression Relief - and this part is the key to the whole thing working right.

So I pulled gear and found only the top half of the part in-tact. The bottom of the part - the half-round section had broken off and was down in the bottom of the crank case. I found it with a couple of bamboo skewers after fishing around for a while.

The fix - less than ten bucks on ebay. I picked up a set of gaskets, the little set screws, a new exhaust gasket off another site.

Put everything back together and she started right up. It's rainy and cold today - there's no way this machine would have started on a day like today...

The fracture on the part looked like it started at the reduction in material - right where the half-round section starts. The fracture was brittle - it started as a crack and worked back and forth over time. This explains the gradual onset of the problem - maybe. Part of that theory doesn't make sense to me but the part did not fail suddenly. The fracture slowly progressed across the half round section. Once it broke, I don't see how the broken section could have stayed in the cam slot but maybe. If it managed to ride in there for a while it could explain why it would suddenly crank like normal sometimes - but only after the oil was warmed up. Still - I don't think this explains everything.

My mower - 8 year old Toro Z4200 purchased new at Home Dept - Courage 19 SV590. You can find the manuals on line in PDF form, the parts websites have excellent drawings. I found this solution by going in after it. I didn't know what I was going to find, and everything I read on-line pointed to fixes that didn't work in my case.

Hope this helps someone else with the same engine (or similar). I ran with this problem for several years until it finally got bad enough to keep the engine from starting except in rare moments.

Thank you for taking the time to post. I'm getting ready to dive into a courage 17HP w same issue.