Help Kohler 25 Fuel System????

[MOW ED]

I believe that I have a bad Kohler 25hp engine. In fact I know I do. Two major repairs in the first 200 hours both covered by warranty (scored cylinder and the dreaded blown head gasket). <br>Now my problem is the mower starts and will idle fine but after it heats up 20 minutes or so it stutters and looses power especially when under load (mowing) what could be wrong?<br>I changed fuel filters and flushed and cleaned the gas tank but the same still happens and it is always after it warms up.<br>Is it the fule pump or dirt or what I'm not real good at the technical mechanical aspect but I know something is wrong.<br>Will someone help, I'm in the middle of big time dethatch season. thanks, ed

[osc]

This engine has a fuel solenoid on the bottom of the bowl on the carburator. Possibly, you have a relay going bad, I think there is two of them. To find out if this problem originates from electricity, carefully take a wire and attatch it to the positive terminal on the battery and touch the bottom electrode of the fuel solenoid. Do this when the motor is acting up and if the engine smoothes out then you know the fuel solenoid is not getting enough juice. It is possible that the solenoid itself is bad which would not reveal itself in this test. <br>To check fuel solenoid, turn engine off and touch fuel solenoid with the wire that you attatched to the pos. terminal on battery. You should be able to hear a click when you touch it. If no click, then it's bad. If click then probably is good.<br>Relays generally act up when engine heats up.<br>If your battery is not being charged then a bad relay is more than likely the problem. It may take a while for this problem to show up, especially if you have a new battery. Only trouble with this senario is that Kohlor owns what is on the engine, not the wiring harness or anything on back. That is done by whatever machine this motor is mounted to. That can be a problem when trying to find help. Small shops may not have wiring scematics for your machine.<p>More than likely your problem is electrical unless the previous repairs were not done correctly.<br>If your engine smokes then the cylinders are still bad. If you hear a loud whisping sound while motor is running, then it's a head or gasket. Either way the last guy to work on this machine may not have wired it back up right and fried something. I would start with him.<br>Good luck, I feel your pain.

[JJ Lawn]

Mow ED, Just out of curiousity, what did your dealer do to fix the scored cylinder?<p>My understanding from my dealer and Kohler was that these 25hp engines CANNOT be rebuilt nor the cylinders honed because of the hard finish applied to them. My dealer replaced my engine when I had this problem. <p>Jim

[GrassMaster]

Hello:<p>If you can't find anything wrong with the fuel solenoid & BTW OSC knows what he is talking about when giving instructions on trouble shooting the fuel solenoid.<p>LOL, I forgot what I was talking about. If you find out that the solenoid is working OK. Since the engine has been gone into 2 times already, I would check the intake & exhaust valves, also their clearence. <p>I'm sure this is a Over Head Valve engine & both repairs would effect the valves, so I would really consider checking into this further.<p>Please let us know what you find out?<p>----------<br>GrassMaster - Home: www.lawnservicing.com<br>My Start Up Page www.lawnservicing.com/startup/

[thelawnguy]

Sounds like the engines overheating. I would pull the shrouds just for the heck of it and make sure the fins arent plugged with grass or mouse nest. Also make sure the dealer replaced all the shrouds, one missing will cause the engine to overheat. What kind of mower is it on? If its on a ZTR, i.e., engines under the seat I can promise its almost always caked with grass and dust debris.<p>Bill

[osc]

Mow Ed:<br>What was the dealer's opinion on why the cylinders were scored? Did you use this machine last season during the drought?<br>A lot of engines ingested dirt because of the dusty conditions. In theory, the air filters should catch all the dirt and if clogged, the engine should quit running. What really happens is the choke effect and more dirt gets sucked into the intake at a high velocity. Thus, a sand paper effect on your cylinder walls.<br>Even if you don't change your filter, dirt should not get past it so the manufacturer is at fault. Always tell the dealer how well you've cared for your machine. Never take a machine in for service with dirty filters even if it only has 50 hours on it. Anything that is wrong will be your fault.<br>Anyhow, I was just curious as to what their opinion was.

[Alan]

Don't eliminate the possibility of an ignition module going bad as it gets hot. I'd be inclined to look for a problem with ignition rather than fuel when a hot engine starts cutting out. Also it might be worht checking the fuel lines to be sure that they aren't getting hot enough to cause fuel boiling somewhere. Probably less likely than in ignition problem but it's another &quot;possible&quot;. My own 25 Kohler had the head gasket problem but nothing since then as gone wrong with it.

[MOW ED]

As of last night the prliminary problem is &quot;electrical&quot;. The mechanic ordered coils. The coils are under the motor somewhere so I can anticipate a large $$ repair because he said the motor has to come out of the Walker to replace the coils. <br>On the appearance of dirt ingestion in my first big problem, I have a turbo 3 precleaner into a Donaldson air filter then a Kohler foam filter wrapped over a paper element. 25 to 50 hr maintenance on all and all connections and wingnuts were tight. Kohler looked at this and had no basis to turn me down. The repairs were fully covered.<br>The mechanic was not familiar with the recall bulletin (it wasn't out yet) for the head gasket when the first break happened sohe didn't change them. Of course I have a **** (excuse my french) motor and the head gasket blew a year later. I mow 2 days a week and have 558 hours on this thing and I'm really pissed that I didn't get a new motor, but that is in future correspondence to Kohler. I'll let you know whats up. My next motor will be ANYTHING but Kohler.

[lawrence stone]

Mow Ed wrote:<p>&gt;My next motor will be ANYTHING but Kohler. <br> <br>You can't discount the whole line of engines<br>because of the early problems of the 25 hp<br>models.<p>That would be like saying I am not going to<br>buy a new chevy P/U because of the handling<br>problems of the 1962 Corvair.<p>I have a CV-18 v-twin that's five years old and I<br>have not had one single problem. No oil, fuel, leaks etc. <p>IMHO it is best to wait a few years b/4 buying any new design so the mfg. can work<br>the bugs out of the unit.

[osc]

Both coils do not go bad at once. This dealer has no idea what the problem is. The coils would be bad cold or hot and I'll bet they don't even have them wired correctly. I've been there and done that with this problem on a kohlor 20 horse. The problem you now have is not a kohlor problem. It is in the wiring harness!<br>Talk to a Kohlor distributor directly. But of course, they will just tell you that it's not Kohlor, it's Walker or the the service dept. doing the work.<br>Are you saying though, that dirt ingestion indeed has been an issue?<br>All of the manufacturers have had a problem with cylinder walls because of 1999 drought. None of them really want to own up to their part, which is questionable to some. <br>If you mow in a sand storm in Saudi Arabia, does that void the warranty? I dunno but your dealer is going to say it does. Last year was like a sand storm for us.

[lawrence stone]

osc wrote:<p>&gt;The coils would be bad cold or hot <p>Not a true statment. Many coils are ok<br>when cold but short out when the engine warms<br>up. If you let the engine cool down for a hour the engine will start right up and die<br>again when the coil gets hot.<p>If you ever get a chance to look at a drag race car you will notice the coil are kept<br>as far way from the engine as possible.<br>

[Jason]

stone:<p>Unless on your drag car, you're running a gm HEI ignition, than your coil is integral with the distributor.<p>I do agree however that in certain cases a bad coil will be fine when cold then act up as it get's hot. Have seen it before.

[osc]

First of all, there are 2 solid state ignition coils on this engine. They are located outside the flywheel, one for each cylinder. They really should not get that hot.<br>The alternator is under the flywheel and rarely goes bad. The voltage regulator is mounted on the shroud. It is more heat sensitive than anything else but should'nt get that hot.<br>I seriously doubt that both coils would go bad at once. If one goes bad, then you can pull off one of the spark plug wires on the side you think is missing and you'll hear no change in the motor.<br>This problem is not the kind of miss mow ed is describing. The real problem is if the guy working on your machine does not have schematics for Walker, then he could wire something wrong. If he does have schematics, then he can take a multimeter and find out where the problems is pretty fast unless this problem only shows up every so often.<br>I would not want to pay for 2 coils if the tech wasn't real sure they were bad.<br>I've actually had a service tech wire my coils to the top 2 prongs which are not even electrodes, they are grounding prongs. People take things apart and get screwed up. Either way mow ed, I hope you get it fixed.<br>

[Lazer]

Hello!<p>I've not read this thread before, but did anyone mention the SAM Module: Spark Advancement Module? They go bad CONSTANTLY on Kohler Commands.

[Dave]

kohler has has serious problems with there 25 hp command,overheating thats why they had a bulletin to cut holes in the covers and put removeable plates in to clean out the grass ,a friend of mine had 800+hours on his<br>25 hp had to be completely rebuilt scored cylinders and lifters collapsing from the heat

[MOW ED]

I have my machine back as of noon Friday and I am $260.00 lighter in the pocket. The mower runs fine again and the verdict is this: 1 coil was bad. Both coils were replaced when the mower first broke down in 1998. The first coils were &quot;a&quot; coils, the replacements were &quot;c&quot; coils. Now I have 2 &quot;d&quot; coils. The mechanic replaced both because of a few reasons, location of coils required removing the motor from the mower, and the coils should be matched and an updated coil has been designed for the unit. The labor was $166.60, the coils were 36.90 x 2 and they had to put a new oil filter on at 7.60. Tax of 12.40 and you get another big money repair for my $10,000 lawn mower that just cost me 4 days of lost revenue and jobs.<br> The mechanic is going to try to file a disputed warranty claim for me. I will continue to pursue it to get my money back. I realize that breakdowns occur but I think I have had my share of them for the 550 or so hours that are on my machine so I think Kohler owes me something. <br>I am happy to have it back and it does a hell of a nice job when its running. Thanks for all of your help and information. Time to go to pay for my repairs.

[Retro67]

I have owned one of the old Kohler cast iron engines. I am glad I haven't had the experiences some of you have had with these 25 Commands.&lt;p&gt; I had a choice and chose the Kawasaki 23 with all of the problems you guys and others have had over the last couple of years. Anyone can manufacture a faulty engine, though. I hope I am as lucky as everyone else I have talked to with Kawasaki engines. By the way, I demoed a DC with the 22 and 60&quot; deck. The 23 Kawasaki on my 61&quot; Ferris is &lt;b&gt;definitely&lt;/b&gt; more powerful, by far.&lt;p&gt;John

[thelawnguy]

A hint for kawasaki owners, you best change the oil and filter no more than 100 hour intervals or you will soon have a new anchor for your fishing boat. They are VERY sensitive to dirty oil, esp the design of the OHV oiling system. My dealer stressed this to me, Kawi is a great engine, but MUST change the oil regularly, or else.<p>Bill