Kohler Courage got me stumped

[fordie]

I have a Troybuilt Bronco with a 20hp Kohler engine. I bought it used, about one year old but used sparingly by original owner. It worked fine summer before last during the final month or so of mowing season. I bought a new zero turn this past summer and only used the Troybuilt for hauling my lawn trailer around and some rough area mowing. Mid summer it began to hesitate during startup, like the starter was hanging up. In fact, I would sometimes tap the starter lightly and it would turn over and start. I decided that this winter I would service the mower and replace the starter. Since the original battery was weak I replaced it and since the solenoid was cheap, replaced it also. Bought and installed a new starter after those replacements and cleaning all grounds provided no improvement. Still had the same issue, turn to "compression" and stop. So after some research I removed the valve cover and checked clearances [.005 on intake and .007 on exhaust] also watched exhaust valve for slight bumb from compression release [it did]. While I had the plug out [by the way, it spins great with plug out] I looked for signs of carbon but found none. I am out of ideas, anyone have any insight to help me? Thanks.

 

[banjodunn]

G'day fordie I think you will find the comp release is not working fully I remember going to a school and they told us they were having probs with some of them ( plastic unit on the camshaft they had a mod for it) just can't remember which model it was and cannot put my hand on the relevant book at the moment. If I find the book I will let you know



Jon

 

[deerseeker001]

Welcome from Wisconsin

 

[fordie]

G'day fordie I think you will find the comp release is not working fully I remember going to a school and they told us they were having probs with some of them ( plastic unit on the camshaft they had a mod for it) just can't remember which model it was and cannot put my hand on the relevant book at the moment. If I find the book I will let you know



Jon

I assumed that if I could see the exhaust lift it would indicate the release was working. Not the case huh?

 

[fordie]

Can anyone tell me if the exhaust valve lifts slightly on intake stroke that would mean the compression release is functioning? Can it just not lift enough? I found a site that showed the correct position of the flywheel magnet at TDC and mine seems in the correct position which would rule out timing key problem. That seem correct?

 

[DSM123]

There was a series of that engine that had powdered iron flywheel ring gears. There was a Kohler service bulletin issued regarding this.
I had the same problem with a 26hp and it was a cracked ring gear which eventually failed and destroyed the starter. Approx $300 in parts to repair the thing.

http://www.lawnsite.com/showthread.php?t=373605

Unfortunately the link to the SB no longer works.

 

[fordie]

Ok, I will take a look. Thanks.

 

[dconine]

Change both of your battery cables. A lot of times they put undersized cables on those units and overtime they build up resistance, and in turn you will have voltage drops.

Pretty good chance that may cure your problem. If you can put slightly heavier cables on, I would go that route.

 

[David_Kb7uns]

Friend had shop at local farm store and a few years back they had a bunch of Home Depot mowers with problems on the Kohler Courage engines used on MTD made mowers with the compression release going bad. At the time the parts were back ordered over 60 days out. Turned me off at the Cub Cadet garden tractor was looking at and got the Kubota G2160-60 with the D782 engine.

David Kb7uns

 

[banjodunn]

G'day fordie the ex valve should crack open just before firing on comp stroke, sorry for the delay getting back to you still cannot find my books will have a look out at the farm on the w/end when I am out there.


Jon

 

[fordie]

Change both of your battery cables. A lot of times they put undersized cables on those units and overtime they build up resistance, and in turn you will have voltage drops.

Pretty good chance that may cure your problem. If you can put slightly heavier cables on, I would go that route.

BINGO! Ran a jumper cable from the solenoid to starter, fired right up. Thanks for everyones help.

Hey dconine, any relatives in Tulsa?

 

[banjodunn]

Good to hear:thumbsup:


Jon

 

[fordie]

Well, at least I thought that dconine's thought about cables solved my problem, but I was wrong. Although it did start a couple of times with a jumper cable ran from solenoid to starter, it then reverted back to not turning past compression. I have adjusted valves to .004 on intake and exhaust. The exhaust valve does open slightly on the compression stroke and you can hear it release compression somewhat. This is with the plug out and turning by hand. The flywheel has no damage, and the key is perfect. At this point I have changed to a battery with 350 CCA and with a 100% charge it will start the mower. After about 5 starts the battery will drop enough charge so that it will only start if I roll the engine past the compression stroke by hand, which allows it enough head start to fire. I have enclosed a video that shows how the engine tries to stop at compression stroke. Yes I can use the mower now by maintaining battery at 100%, but this can't be how it should start. Any additional thoughts will be appreciated. Hope this video works.

video-2014-02-02-13-18-07.mp4

 

[crazyal]

My mower isn't as bad but does have a hard time starting. It's got a 19hp Courage engine. It seams like getting past the first compression stroke is very hard. But once it does it'll turn over just fine. I haven't gotten around to it yet but my plan was to run heavier wires (including a ground wire from the starter back to the negative terminal on the battery). Also I was going to remove the battery box and replace it with something larger so I can use a small car battery. It just seams to me that the starter is a little on the weak side and it needs all the help it can get.

If your charging system is working correctly your battery's voltage level should not drop. I would do the basics, check all the connections, make sure they are clean and making good contact. Make sure the starter is making good contact with the engine and the engine is well grounded to the frame. It's not just getting the power to the starter it has to make it back to the battery.

 

[justme23005]

Pop the flywheel off, and take a look at the magnets.. It's VERY common for them to come loose.

 

[Loadstar]

Briggs do a similar thing also I always am lashing valves.

 

[Redneck in training]

Well, at least I thought that dconine's thought about cables solved my problem, but I was wrong. Although it did start a couple of times with a jumper cable ran from solenoid to starter, it then reverted back to not turning past compression. I have adjusted valves to .004 on intake and exhaust. The exhaust valve does open slightly on the compression stroke and you can hear it release compression somewhat. This is with the plug out and turning by hand. The flywheel has no damage, and the key is perfect. At this point I have changed to a battery with 350 CCA and with a 100% charge it will start the mower. After about 5 starts the battery will drop enough charge so that it will only start if I roll the engine past the compression stroke by hand, which allows it enough head start to fire. I have enclosed a video that shows how the engine tries to stop at compression stroke. Yes I can use the mower now by maintaining battery at 100%, but this can't be how it should start. Any additional thoughts will be appreciated. Hope this video works.

video-2014-02-02-13-18-07.mp4

You might have charging issue too. Once you get it started it should recharge the battery. The voltage when running should be about 14.4 to 15V. My Kohler had corrosion in the alternator stator that caused break in the winding. The service guy told me that it was a common issue especially on mowers.

 

[Dave M7040]

The path from the ignition switch to the starter solenoid goes through many safety switches such as is the blade disengaged, is the brake pedal depressed. Each of these switches adds resistance to the circuit which will power the starter solenoid. As each of these switches gets old, the voltage to vigorously pull in the solenoid is not present and the solenoid contacts become pitted. Run a temp wire from the battery to the solenoid terminal and I think you will be amazed by how strong the starter is. Be certain to have the blade disengaged and the tractor brake on when you do this. If I am correct and this shows the starter and engine are fine you have two options. The first is to replace the safety switches. Alternatively, use a headlight relay to power the starter solenoid. Engage the headlight relay with the wire from the ignition switch which is passing through all the safety switches. Provide power to the headlight relay from the battery terminal on the starter and connect the output from the headlight relay to the terminal on the starter solenoid.
Dave M7040

 

[fordie]

Thanks for all the thoughts. I did run the jumper as I explained. The charging system is fine, the battery drain was from repeated test starts. I was just indicating that a slight decrease in battery strength is all it takes to create a no start. The only safety switch in place is the brake switch. Disconnected the others when I bought the mower. Yes, I checked all of those areas for corrosion. This mower is only three years old and is stored inside. I was unaware of the magnets under the flywheel, I will check that. I like the idea of the relay and will try that. Thanks again.

 

[Loadstar]

Contacts pit overtime no matter what lol. If you want a good power upgrade go get an old ford solenoid from auto parts store. They are cheaper than the cheapo mower relays and you will get better cranking. Also you will not wear it out or melt it in half like the mower solenoids are good for. I think you are on the right track with compression relief. I have battled it time and time again with b+s engines.