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K341 Rebuild?

L

Lead Head

Guest
Hey guys,

I've got an older Kohler K341-S in an old hydrostatic Allis-Chalmers 416 tractor.

The engine is starting to burn a lot of oil. The only time it does not burn oil is if it is brand new SAE 30. Once it gets about 5 hours on the oil though, it just starts burning it like crazy, and lately i've been noticing some oil on the muffler, coating some of the fins on the starter side of the motor. When I had pulled the head off in July, had noticed that the cylinder bore seemed to have a gap around the front and back side of the piston.

I'm guessing oil on the fins and spraying on the muffler is from a bad rear seal.

I guess my question is on average, what is the cost of having the block bored/honed out, and valve seats reground if needed.

I've seen rebuild kits on ebay that include all the gaskets, connecting rod, piston and new valves, but I have no idea if t these kits are any good, as a brand is usually not listed.

Thanks in advanced.
 
S

Sky

Guest
Getting the block bored, honed, valves done ect. vary's from place to place, machine shop to machine shop. to get a cylinder bored and honed cost around $35 here. i've never had valves done cuz i do them myself. If the cylinder is wore bad which Kohlers are noted for, then go .010 over
that usually cleans things up. Just for the heck of it i would check to see if your crank case breather is clean first cuz when they clogg they can give same effects as if rings were bad. If you do proceed with the rebuild, try to stick with name brand parts as much as possible. avoid after market if you can. Genuine kohler parts will be stamped "Genuine Kohler" or just "Kohler"
If there after market, chances are they will be marked "Stens" are some other after market part maker.
 
L

Lead Head

Guest
The breather is fine, I still see vapor coming out of it when its running, but I do recall when I cranked the engine with the head off, a significant amount of oil was coming past the rings.

I'm honestly not sure if .010 will be enough to bring the bore back into spec, I might need to go to .020, I really don't want to go .030, because I think that might compromise the integrity of the block.

I didn't know the K series were known to have wear issues, I thought the K engines were considered to be some of the best for their time. Although, I bet part of the issues with my engine is that my father never took proper care of the engine, never put oil in the cylinder during the winter, irregular oil changes, etc..
 

W.P.Klein

Sponsor
Last Subscription Date
01/19/2020
We can provide you the parts but you can also get Kohler parts closer to home I am sure. If you need anything for the tractor drop us a line from our website. www.sandylakeimp.com
Bill Klein
 
L

Lead Head

Guest
Sandy Lake? I've contacted you guys before regarding some replacement parts for my Allis-Chalmers 416 (ignition switch, and other misc things).

Anyways, I'll see what we have local around here.

A bit OT, but you wouldn't happen to know what kind of oil and hydraulic fluid the transmission takes, as well as that gear case that takes the engines drive shaft and turns it into two pullies?
 

Bill Geyer

Registered
Age
73
Last Subscription Date
01/30/2013
The vapor you see at the breather is an oil mist, and will coat everything, you are on the right track:)
 
S

Sky

Guest
definitly sounds like rings to me then. you can do what you want but .010 over is alot when it's said and done. dont sound like much and it isnt much acording to feeler guages and what not but when you have them bored you imidiatly see the diference. Kohlers were considered to be the best and to some loyal Kohler owners, they still are, now i dont know if they corrected the problem through the years, but some of your older Kohlers have a real short rod in them, good example is the k241 and the K341. The engines also had real sharp revolutions in the rod each engine cycle. ALMOST rocking at a 40 to 45 degree angle with the crank at the 9'Oclock & 3"Oclock position. add shortnes and that mild of angle of the rod and you get a cylinder that ware's egg shaped. Also ware on the piston skirt. Im not saying your engine will have this but dont be suprised when you pull the piston out to find perhaps scuffing on the skirt and a little perhaps, towards the top of the piston, and then again, it may turn out to be alright, but from your description, i'd still have it bored. usually you have to, other wise it stands a good possibility the engine will pop the new rings.
 
L

Lead Head

Guest
Yeah, I have some pictures of when I first took the head off at in July.



One of the portion of the bore facing the valves, you can see where the oil was coming up and being burned, it was just kinda a ridge of carbon bulid up there. That is AFTER i scraped tons of crap off with a block of wood.

I don't know anything about cylinder bores or anything, but looking at the picture now, the bore looks pretty well worn to me.

I find it kinda humorous that a little portion of the piston still looks new :D
 

K D Redd

In Memory Of
I've seen many like this. You will most likely need to bore the block. Pistin are available in .010, .020, and .030 inch over size. Clean the top of the piston well as the current size of the piston should be marked.

Kent
 
S

Sky

Guest
yes. make sure that piston is marked when you put a new one back in. That little chamfer to the side of the piston there, make sure that points to the flywheel side during assyembly. Thats how it should assyemble. If you are in need of any kind of torque specs i can give that to you aswell. if you need it. :)
 
L

Lead Head

Guest
I found the torque specs on the kohler site, the only problem now is that I need to acquire a torque wrench :p
 
L

Lead Head

Guest
Well I got the engine off the tractor, and somehow got it onto my work bench in the basement. I got the head off, and thankfully the cylinder bore was not as bad as I thought it was, and .010" will probably work just fine.

I managed to get the shroud off, with difficulty, I stripped two of the screws that held the preferated metal sheet that goes over the fan intake. Just like I had thought, there was oil convering a good chunk of the flywheel side fins, but the thing was, there was no oil on the flywheel, or anywhere I could see between the flywheel and the block, and none leaking below the flywheel. Maybe the headgasket was leaking, and it was pushing oil through? The bolts on the flywheel side of the head did not take much force at all to break free.

I supposed next will be to get a flywheel puller , because apparently, its not the best of ideas to hit a cast iron flywheel with a hammer
 
S

Sky

Guest
You know, if you need a torque wrench, i have a spare. brandnew. It's the old beam type wrench with the needle indicator and it's not a craftsman but it's still a good wrench if you needed one. Private message me if you want it. all i want is what i gave for it, which wasnt that much, plus shipping.
 

Andrew Mackey

Moderator
Last Subscription Date
05/14/2017
Lead head -
To remove flywheel - remove hold down nut, starter cup and washer(s). replace nut, by hand, until end of crank is just below the face of the nut. With a couple of pry bars, put slight pressure on the engine side of the flywheel (DO NOT pry against the tin work). Using a brass mallet or aluminum spacer and a regular hammer, sharply rap the crank nut. This should pop the flywheel loose on the shaft. DO NOT hit the end of the shaft, or the nut directly with a steel hammer, as you will deform the soft steel crank!. Definately clean off the top of the piston with a fine wire brush and some carb cleaner. There should be a stamping - STD, 010, 020, 030. and an arrow, facing 'front'. make sure to replace new piston in same relation, (Some engines do not have the arrow - note direction of size stamping, and set new piston in same manner. As a rebuild tip - use 5W-30 as break in oil, for first 5 hours of use - load moderately, and vary speed form idle to full speed. Do lot load fully for 1st hour. This will seat the rings quickly and cleanly. After break in, follow needed specs for oil. The K series engines, especially the ones made in the 50s thru the late '60s were Kohlers best! They were considered the Cadillac of the small engine community. They outlasted, out performed anything in their class. As long as they had oil (and sometimes even if they didn't), they were indestructable. Now days, rebuild kits arn't cheap, but for the Kohler Ks it's worth every penny.
In looking at your photo, I see some cylinder streaking, probably from wear of the piston rings being worn, and carbon getting stuck along the side of the piston. While you are checking out the engine, have a look at valve guide wear. With each valve wide open, try to wiggle the valve in its guide. there should be very little movement. If you can rock the valve more than about 1/16" at the head, probably new guides and valves are due. The guides are available, and so are the valves. remember to clearance them properly as well. Lastly, check for play in the throttle shaft in the carb. Too much slop will compromise throttle positioning, and will cause fuel mixture issues (Poor idle, speed transition stumbles etc). Remember to re-torque the head bolts after the 5 hour break in period as well.
Andrew:D
 
L

Lead Head

Guest
I cleaned the piston off some more and I see 'STD" stamped on it, so I'm assuming this engine is pretty much stock then

Here is an overhead shot
http://i25.tinypic.com/23rs1za.jpg

That oil in the side of the piston, is just from turning the crank by hand - and all the oil has been drained out of the engine already.

http://i26.tinypic.com/i76gdc.jpg
Here is an over all shot,(just for fun I put it next to a small (and very old as well briggs)) what still has me confused is the oil on the fins right there. I'm thinking that oil made it past the headgasket, but I'm not sure if the engine could even still run with decent power if the headgasket leak was that bad.
 

K D Redd

In Memory Of
Most shop that use a boring bar will want to bore your block .020 over. This is because you can not center a boring bar EXACTLY. I have a boring hone which I useto bore block but you cacn neverbe sure of the wear in a cylinder until you MEASURE it with a inside micrometer.
I rebuilt a K-301 last spring that I thought would clean with a .010 overbore BUT when I had it 10 over there was a spot the size of a silver dollar halfway down the bore that had not cleaned. THAT is when I used my dial bore gauge to check the spot. I found it was about .017 over. I had to bore the block 20. The owner said this engine had had a bad knock which I guess was piston slap not the rod.
This proves you never know WHAT you will find until you start the boring process.
Kent
 
L

Lead Head

Guest
Well, I've hit a slight snag. I can't for the life of me figure out how to get the oil pan off, I've taken off the bolts, and flipped the engine on its side, but it feels pretty well stuck.
 
L

Lead Head

Guest
Good news! Got the oil pan off, and got the piston and connecting rod out

Bad news: the piston skirt is not smooth at all, feels rigged. Theres a chip missing from the side of the skirt, as well as a part gouged out, and it looks like the crankshaft will need resurfacing as the part the connecting rod connects to
has a bunch of groves, like something got stuck in it.
 
L

Lead Head

Guest
To add on, since there is no edit button, the cam gears, and all other gears showed no signs of being gouged or even signs of wear for that matter.
 

David Brinkman

Registered
Heres a website with a lot of information about rebuilding Kohler's either stock or modified hope it helps.

http://members.aol.com/pullingtractor/tips.htm

This information about imported parts is from the website.

Imported pistons, rings, rods and other parts hold up VERY WELL. I should know, I've used these parts in my own equipment and I've sold them to my customers. I've sold many of these parts for the past 26+ years and I haven't had one complaint from anyone. Besides, it's how well the engine block and crankshaft are machined (cylinder bored straight, crank journal reground to OEM specs, cleanliness of the parts and work area, etc.), that determines how well and how long internal engine parts hold up. Don't blame shoddy workmanship on shoddy parts.

I'm currently re-building a K321 that had a broken rod. Took the block to the automotive machine shop yesterday. They are going to bore it out .010 and grind the crank under .010. I ordered a re-build kit from ebay. Should be like new when all done.

Dave in South Dakota
 
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