k321 rebuild
 

I am going to be off work for a couple weeks to hunt rabbitts but wanted to also take some time to find out what the rap may be that I posted about earleir. My question is, apx how much does a rebuild cost on a 14hp, and apx how long would it take. I know that there are all kind of variables in that question, but just looking for ruff ideas.
Thanks

Are you going to do any of the work, or farm it all out and have it done by a shop?

I was going to do, unless it needs bored out, or the crank needs work. I have a well equiped shop. I'm not qiute sure what the rap is, I hope it may just need a rod cap or some replacable bolt on part that I can go to the dealer and get, I has never used oil so I'm just not sure what I'm looking for.

I rebuilt the 12hp motor in my 128. I had to have the block bored .010 over and the crank pin cut .010 under. Mostly after market parts were used except for the governor pieces and the rod and head gasket. I have about $400 in my rebuild.

I just did my K341, here's the approximate numbers:

Stens rebuild kit, ebay: $125
Machining, bore and crank: $105
Carb kit: $15
Kohler head gasket: $15
Muffler clamp: $4
Governor gear, shaft, and bushing: $40
Camshaft shims: $9
Oil: $5
New head bolts: $5
Valve breather filter: $5
Carb gasket: $5

That's about it as far as I recall.

CC1650dave, what did you have machined on the crank, did it need a different rod cap after machining?

I had a K series that the balance gears were knocking, I just removed them and the engine was fine.

CHWNY
I put a heavy load on the engine while pulling a Brinly plow and thats when the noise started. It had been running fine up to that point. What causes them to come loose? What were the symptoms with your noise.

Yeah, I had the crank journal turned to .010" under. When you order your rebuild kit, you specify that you'll need a .010" under rod.

I think the bearings are too small for the load and don't seem to get enough oil, when you take the oil pan off you will be able to wiggle them if bad. You should take the crank out to remove them! At least remove the rod cap to check the bearing surface there. One gear will come out easy, You could break the other one out w/cold chisel and BFH, not the safest way but worked for me.
My engine would have a slight knock; like a rod @ throttle up and under load. There is much debate about removing the gears, however in my case there was no real difference, slight bit more vibration no more than my Harley flat head though.

Ive done a 12hp for around $150, that included some machining not much, we do everything else our selves.

Stoped at the dealer today and got a head gasket and pan gasket. Hooked up my old computer in the garage and have it on the wireless network so I can get online while I take this apart. I hope to start taking the engine out tommorrow, but snow today and cold, so will have to wait and see. Tractor is in an unheated building and thats were I am going to pull the motor out. Put a pan under the motor and am letting the oil drain over night and hope not to find anything in the drain pan. Any do's, don'ts, or don't ever's would be appriciated. What you discribed CHWNY is about what it sounded like and I hope is whats going on.

As far as "do's", simply read, understand, and follow the service manual during disassembly. It will lead you down the right path. And of course, let us know what you find. :)

krhoover,
I just did a K321, bored the cylinder turned the crank -.010, machined valve seats, that cost me $85, new Kohler piston and rings +.020, were $100, Sterns Rod, complete gasket kit , head gasket, governor gear, governor pin, several other small items $150, points, point wire, new exhaust valve condensor $30. Carb rebuild kit $15? oil $15, plug, paint $20. Stens kit would have been cheaper. I did not add this up but would budget $600.
I removed the balance gears. And I do have a little shake at idle but just adds to the effect:(
Watch the clearances for the crank end play. Watch for shims on the cam shaft and the governor gear very easy to loose these. Tough to see! Watch for getting the timing marks on the crank and the cam in the right spot. Get a good manual.
Good luck and take some pictures as you go they may help you get it back together.
Regards,
Chris

Got it out and apart with no problems. I can't see anything wrong with it. Nothing in the oil pan, everting seems tight, no scoring of the crank or rod cap. There are no balancing gears, at least I don't see them. There was oil in the valve cover area. Also, see the cross shaped piece that was in the valve cover, is that factory or homemade? The large cam gear tooth has a chunk broke out of the one tooth, but I don't think it would affect anything. Can anybody see anything else from the pics? I am going to get some spray can cleaner and spray the inside of it down and clean the head up and take another look. I am going to pull the valves and clean them up and set them per the manual. While it is down this far what else should I do? Another question, I want to do the cradel mod, will a piece of 1 1/2" x 3/8 work instead of the 1/4" thickness. Also note in the pics the two different types of ISO mounts.

Done for today. Got the valves out and cleaned them up, am going to pick up some lapping compound and lap them in. I just don't see anything that would have been making the noise. So unless anyone has any ideas or sees something in the pics, I'm closing it back up. Now to the other issues I have found. The wire connector to the front electric PTO was melted. The pulley it self was awful loose but it did tighten up. It is very oily, wich makes me wonder if a seal behind it is bad. Can they be rebuilt? I hope the melted wire was from high amp draw from the loose pulley. What can I spray it down with to clean it up. I would like to take it off and disassemble to clean it. Now to the cradel mod. Can it be done in the tractor or do I need to remove the rails to weld the piece on? When I put the motor back in, is it easier to bolt it to the rails out of the tractor and then bolt the rails back in or just bolt the motor back in. The reason I ask is I had a little trouble bolting the oil pan in while looking at the cradel mod. I think i read that that was the way someone did to get it to all line up before welding. I'm guessing its from the ISO's being flexable. I see that the pic of the rails didnt show in my previous post. Here it is. Lots of questions, thanks for the answers.

That chipped tooth on the cam is not good. Maybe it's just the picture, but it looks like several other teeth in the vicinity are also damaged. If it hasn't already damaged the gear on the crank, it probably will eventually. I'd get another cam. Where are all of the pieces?

I would remove the engine mount rails to weld in the brace...it is much easier that way. I would also replace the crank seals while you have it this far apart, since you seem to have an oil leak. I think it will be easier to reinstall the cradle first and then the engine. That piece in the breather is factory.

On your cradle mod:

You'll want to take the rails out of the tractor, and then use your oil pan as the jig to hold the rails in place while you weld in the crossmember. That's the main thing, that your oil pan bolts back up perfectly.

Regarding the thicker piece of steel, your oil pan will tell you whether that's feasible or not. I think you may need to move the crossmember forward a little more than the conventional placement, but I can't remember exactly. Watch the clearances you need for the bolt heads that bolt the oil pan back to the engine.

On reassembly, I put the rails in first, then dropped the engine in and bolted it up to them. I think it'd be difficult to get the ISO's in while trying to shoehorn the whole thing in there.

If you have any problems with getting things lined up, see my 1450 Sub-Project thread. I found an issue that caused problems and solved it. If the oil pan bolts up nicely after welding, the rails are straight and ready to mount. Don't bend them around!

I don't know if you dropped your front axle or not, but I recommend it. It makes it 10X easier to get those front engine bolts in. Also, use lock washers on those engine mounting bolts. I think that was a flaw in design not using them with all that vibration. Both of my QL's were missing bolts.

The seal on your PTO side is replaceable, and it's cheap to do it. That's something I'd definitely do - both main seals - while you're in there.

You're this far, I'd check it out good while you've got it out. Someone else can give you much better advice on what all should be checked out, but I'd certainly have the bore checked for roundness and see where it's at to spec.

Check the BOTTOM of the bore, where the piston stops traveling, reverses and starts back up.

I had a K321 wear the cylinder so bad at that point, it broke off the piston skirt.

That engine had MANY hours of high grass mowing, I was hard on it!!

I just hand sanded the ridge smooth, put a new standard piston in, and kept running it.

I was a little easier on it after that.

Before you the valves back in put in new valve guides if the motor smoked on start up it will fix that. You have to ream them you can do that with a 5/16 drillbit. You drive them out from the top into the breather area with a 5/8 bolt

Awesome pics too!

A drill bit is for drilling holes, and a reamer is for making them a very accurate diameter with a very good surface finish. A drill bit will do neither of those things. Use the right tool for the job.

Thanks for all the info, advice. I have a freind who's relative builds racing engines. He' going to grind the valves for me. I checked valve clearence with a feeler gauge before taking out the valves, they were wide. Could that have caused the noise I heard? It didn't smoke on start up, but will look into the valve guides, if they drive out from the top, I assume new ones are put in from the top? I have this old motor that is a K301as, would the cam fit this 14 hp? Are there any seals or bushings that need replaced when putting in another cam? Is it hard to change out? I thought about using a dremmel tool to round off the edges of that chipped tooth. Matt G, the other gears seemed okay, I think thats just the pic, but will look them over. I didn't see any metal chips or filings of any kind in there, but didn't check the pan I drained the oil into, thanks. The piston has STND stamped on it along with some #'s. I checked the bore dia, with a set of calipers and got 3.497", and cant feel a ridge on the cyl wall. Would milling some off the head help in any way? I could ask the guys at work do that. If so, how much? What about the electric PTO melted wire connector, and rebuilding it. Also did you notice the two different types of ISO in the pic. How can you tell if they are bad. The two in the front are smaller and the rubber seems softer than the two rear ones. Setting up the PC in the garage was a big help, had this site and all the tech stuff a click away.

meanwhile
 

I'd spray some oil in there before bearing surfaces begin to pit.

jbrewer, that pic is of a blown k301s that I was refering to about using the cam out of it in the k321s, but thats not a bad idea, I,ll do it as its stored in an out building.

Governor gears
 

Someone mentioned the engine knocking noise. Mine was doing that before I tore it down. The governor gears were loose in there and practically fell out on their own.

I wish I had taken the governor gears out and put it back together and see what happened, but I didn't think that far down the road.

Looks like if they came out during operations they would digest into the moving parts and tear up something for sure.
Dave in SW Missouri

The 12 hp cam is the same...I would not take a chance on the one that's in there. You'll need bearing plate gaskets. Also, you cannot measure the bore, piston, crankpin, etc with a pair of calipers. A micrometer is more accurate, and therefore the correct tool. There are details in the service manual about correctly measuring the bore.

Getting the valves ground tommorrow. I was mistaken about the blown motor I want to swap cams with. It is a K241as. Will it still work. And when switching the cam, do I use the rod that was with the used cam, or should I use the one out of the motor I am putting it in? I put a pic up that shows the field (?) of the electric PTO. The insulation looks bad on it to me. That prob is why the wire connector was melted. It also needs a bearing. I haven't looked for repair parts for it yet and don't know if there available. If I remember, I think the dealer told me he didn't think so. I'm wondering if an electric motor shop can wind new ones in there? The pics of the ISO mounts show two different kinds. The small ones need replaced, which are factory and which are aftermarket, one of the front snubbers are gone also. I did the cradel mod also. Matt, I used a set of veneer digital calipers to measure with, but could only get down the cyl wall about an inch. I will ask the guy doing the valves to mic things out for me. I'm sure I'm forgetting something, so I will be back for more advice for sure, thanks

The K241-K341 cams are the same, so that will work. I would keep the pin with the cam.

If any of those ISO-mounts are soft, they need replacing. Those you think are aftermarket look a lot like the new OEM mounts.

You might be able to get the clutch coil rewound, but buying a used clutch would probably be cheaper. Or you could rewind it yourself, but that is not a project to take on unless you are ambitious.

There are two different sizes of ISO mounts, and the bigger ones look new. The two smaller are wore out and are soft. The other thing I forgot about was the govenor gear. From what I can see, the gear in the 14hp is plastic. The one in the k241 is steel, is it better than the plastic one and should I swap them out? Also, since this 14 hp has the std piston in it, would just a set of rings make any difference? It didn't notice it useing oil.

I will be going to the dealer today to get gaskets. So could someone tell me if new rings in this motor will make any difference? Also the question about the governer gear. (from previous post)

Depends on the bore size have you had it checked per the service manual? People will say yes it did with mine or say no it didn't with mine, until you get it measured per the service manual you'll never know. Size does matter! Replace the governer gear and the push pin for the points. Pull and remove balence gears.

Alot of people like the old cast iron governor gears for their pulling machines in that they are pretty much bullet proof. If the teeth look good and all the weights are working, I would use that one as opposed to a plastic gear. I know that they usually sell for @ $40 or more used.

I agree with Duke on the ring issue. Until you know the measurements of the cylinder IE: well with in spec or borderline you won't know what to do. Also if you don't see good cross hatch in the cylinder, new rings probably won't do a thing for you. If the motor wasn't smoking or burning oil I would leave what you have alone, unless you plan a full rebuild.

Got the valves ground today. While there they checked all the tolerences on the engine crank and piston, and everthing was well within spec. I'm just going to do the cam and governor gear swap, change the crank seals, replace gaskets and close it up. I guess that noise must have been from the piece off of the camshaft tooth. On another note that may be off interest and help tp others, I took the electric PTO the motor shop today also. They did a test on it and it was okay also. I asked about the bare wires showing. The guy told me that they could be covered agian with a two part epoxy. He took his finger nail and picked off more that was loose. He said to get off what I could, but to be careful not to remove any of the clear insulation on the copper wires. I used a spray made for cleaning electrical contacts prior to taking it to him to remove the oil from the leaking crank seal. I would watch if you clean them to use the right stuff so not to remove the coating.

I am confused about the oil seal on the bearing plate as far as the depth. The nanual says to set it to a depth, but I'm not sure as to the depth from where. It also shows different types of ignition as to what depth for each type. This engine is a 14 hp out of a 1450. I cant get the pages to attatch, put they are pages 12.10, 12.11 in the kohler manual. I hope you can understand what the question is.

The bearing plate seal should be pushed in till you have 1/2" clearance from outer edge of bearing plate to shoulder of seal.

The seal on the PTO end will be 1/8" from outer face of the crank case to the seal shoulder.

Which edge is the outer edge, the edge on the bearing side or the edge on the flywheel side?

Flywheel side.

thanks that helped

Got it all togather and am very pleased with the way it's running. I don't what happened to it to start with, unless it was that chipped timming gear tooth going thru it. Thank you all for the advice and help. Now a few more questions. The first one deals with the setting of the RPM's. It says to set it @ 3600. I will have to get or borrow a tach, but won't the governor self regulate the RPM's? The other deals with the steering column. The valve for the hydralics is mounted to it. When the arm to raise and lower the lift on it is used, the steering column moves up out of the gear housing at the bottom about a 1/4". The breakdown in the manual dos'nt show what holds the column into the gear case. Is it welded, pinned or what. I wish I would have seen that while I had the motor and gas tank out of it.:bash2: