[Moetting]

So i picked up a 312 yesterday. I didnt need it, but it was cheap, in good shape body wise, little to no rust. Small home made wheel weights and a brush guard. That pins on and off just like a normal attachment for the front of a 3xx series. I got it loaded in the trailer using the not finished 318 and after I moved the 78 sears ss10 and the cab and blower, got it home and started looking.

It will turn part way over by hand, then clunk and stop dead. It will roll over back the other way and same thing. This is just my hands on the driveshaft. No tools or anything else. It feels like it is coming from the engine, not the hydrostat. Im guessing a dropped valve? It doesnt feel like it has compression but I pulled the spark plug and stuck a screw driver in and it moves when rolling by hand.

Is this thing worth fixing to use as a mower? It has the 38" deck on it. No front hydros but has 1 lever for raising the deck so Im guessing they could be added if I wanted, maybe at least 1 rear and 1 front set to use a 2 way blade or raise and lower a dump trailer I still havnt had time to start on.......

What is common in the k301? Is it worth repowering? or maybe just a used motor? I will try to get a pic up tonight, and when i say cheap, it was $50 bucks, so i think its at least worth looking into.

 

[burned300]

yes, its worth it. those valves never see the piston, you may have a broken rod getting jammed on block.:wwp:

 

[1969140]

What you would be touching with a screwdriver through the spark plug hole is a valve, not the piston. Probably the engine has a broken connecting rod. May or may not have trashed the inside of the engine.
I've had a 312 for several years and use it as a tiller tractor. if the engine is fixable with not a lot of money go for it, if not maybe you can find another engine.

 

[Moetting]

Rod is definately smoked, head is off, piston doesnt move. Pics as promised

 

[Moetting]

so here is what I found...........



Not sure if I should repower with a used k301 or spend 80 on a rebuild kit and pay a machine shop or option 3, rings, rod, piston, head gasket and let her mow a few years. Im leaning toward option 3. There isnt a noticable lip in the cylinder, not much wear anywhere really. No aluminum on the crank from the rod. Worst part is there is a small hunk broken off the bottom of the cylinder. I dont think its far enough up to matter, but......

Suggestions?

 

[Cementhead]

I fixed a lot of those iron Kohlers that broke the rod and they usually do break a chunk out of the lower cyl where it protrudes into the crankcase,it usually doesent affect them.If done right that engine has many years left on it.One I remember in particular was on a JD 212 back in the 70's at the shop I hung around as a kid.The block had a crack and we had it welded up rebuilt the engine and it ran for 20 more years being used weekly for mowing.The owner finally drove it out by the road with a FREE sign on it because the deck was shot.

 

[biker3777]

All the k motor.s seem to break like that,,anyone ever hear why they fail at tha t point,looks like it has plenty of material there.I think the Onans break from low oil and heat on one .side

 

[Cementhead]

All the k motor.s seem to break like that,,anyone ever hear why they fail at tha t point,looks like it has plenty of material there.I think the Onans break from low oil and heat on one .side

Low oil is usually the culprit Biker,some claim if you do too much sidehill it will rob the sump but I don't buy it.I did some awful sidehill with those engines and never had one fail from it but I did run the oil level a little over the full mark on mine.Overspeeding is definitely another cause from gov problems.

 

[biker3777]

Tks CH,rpm would have been my guess,one reason i set mine to run a little slow( 20-30 ) years old deserves a break.just my opinion.

 

[rabbitking61]

The one flaw with a 312 is they don't have a very sharp turning radius. Other than that it isn't a bad mower.

 

[Moetting]

The guy did say it revved way up and then clunk, never moved again. so he went and purchased a x300 new. His property was extremely hilly also. guess ill need to look into the governor also.

 

[Yooper75]

I went through my 312 two years ago and the only thing I did internally to the motor was measure everything to make sure it was in spec then replaced the seals, gaskets, main case bearings, and she runs like a top. Run good quality oil, change it often, and make sure it's always topped off and you shouldn't have a problem with that motor I also run it WOT all the time even side hill mowing.

That oil looks nasty! How badly did it smell like gasoline?

 

[Moetting]

The oil didnt smell like gas but man was it thick and had lots of metal in it. I had the pan upside down for 2 days and it still hasnt all run off of it yet. Its probably the worst i have ever seen.

 

[Diesel332]

I never run my 214 at WOT so there is room for error if the governor and carb are adjusted incorrectly. I make sure the carb is at 3550 RPM every mowing season. I don't like to run my Kohlers on a hill, but I'll do it once in a while. My 332 mows my back hill and my 214 mows my front yard.

 

[Yooper75]

The oil didnt smell like gas but man was it thick and had lots of metal in it. I had the pan upside down for 2 days and it still hasnt all run off of it yet. Its probably the worst i have ever seen.

I would probably say that it broke from lack of maintenance if the old oil is that thick and nasty.

 

[Yooper75]

I never run my 214 at WOT so there is room for error if the governor and carb are adjusted incorrectly. I make sure the carb is at 3550 RPM every mowing season. I don't like to run my Kohlers on a hill, but I'll do it once in a while. My 332 mows my back hill and my 214 mows my front yard.

You are actually doing more harm to the motor running it at anything less WOT. An air cooled motor needs to run at full throttle to get the volume of air it needs to cool it's self and the engine oil. The other thing it's doing is you're running at closer to 100% load on the motor all the time because the flywheel doesn't have the momentum it needs to keep ahead of any load the motor may encounter such as turning on the PTO. The other reason to run at full throttle is you can potentially oil starve the motor because it rely's on oil splash from the crank shaft instead of a pressurized oil system like your 332 has.

There is a reason why the owners manual says to run the motor at full throttle.