kohler k241

[Martin 2,132]

i got this kohler k241 from marshall (indywh) at scotts meet and greet last weekend. i was after either a good runner or something i could rebuild for a future project. i figured i would get it running or tear it down and post my findings as i go. im no expert but know a little about how these things work and can usually get most of these things running without too much bother. i aim to show how somebody with limited knowledge such as myself can hopefully get a decent runner out of something not running. i dont really know much about this engine other than it was originally off a 1057,1067,1077 (spec 46333D) and it spend some time out side in the weather.........

the crank was free and turned over fine, but it wouldnt go more than 1 1/2 revolutions before coming to a stop. it would then turn the other direction the same amount then stop again. i had to work out what was stopping it from turning over before i could go any further towards getting it running. since it was going more than the one rev i figured it had something to do with valve/ cam as it turns half speed to crank revs. i figured id start with valves and see if i had something seized there. marshall mentioned that it had spent some time outside so i figured at least we had some valve stems seized in their guides.

removed carb and checked out the intake......

yummy.......

carbs gonna need a rebuild too.....

removed head and checked that we had no dramas with the piston/connecting rod assembly as it was being turned. everything was good and felt ok, didnt sound like there was much play in the big end, and the bore although a little glazed didnt look scored. fair bit of carbon and crap there, this concerns me a little.........

anyway intake was stuck, but nothing a bit of blaster didnt fix. intake wasnt stopping the cam though, as removing the cam gear cover verified. exhaust cam follower seized in bore and was stopping cam lobe from actuating exhaust. it would touch and then just stop the cam dead in its tracks.

managed to get the follower free, but still having trouble with the exhaust valve tight in guide. so i will work on that.

i would like to get the valves free and get it back together and at least get it running to see what its like. it already has a .020 piston so the bore has been opened already. if it does need boring then i hope i can save it and until i get to the bottom end i wont be sure what im dealing with there.

if you ever need to remove the exhaust on one of these things the safest way is to just cut it off within 1/4-1/2 inch of the block and deform the pipe like in the last pic with a cold chisel or drift then the collapsed pipe can then be easily removed without damaging the threads in the exhaust port.

this is as far as ive got at the moment, plan on getting the exhaust valve free if possible and cleaning the bad areas such as the ports and valve cover/spring area, then we will try and get it decent enough to run. i guess thats my best case scenario. if the exhaust valve guide wont free up im not going to push it and will just tear it down and rebuild it.

[rmaynard 15,514]

She's a beauty aye? Barring any major problems like a crack, I know you will have her looking and running like she was meant to. :thumbs2:

[Martin 2,132]

She's a beauty aye? Barring any major problems like a crack, I know you will have her looking and running like she was meant to.

well im hoping so bob.

i would like to have a happy ending here, with not a lot of $ but if it needs a rebuild then i guess i will cross that road when i come to it. and hopefully no cracks! everything i come across engine wise doesnt run when bought, but its been fairly easy to get em going. i guess this one will be the most involved as it has involved tearing into the internals already. i enjoy the pursuit of making it a running machine again. would be easier to find something running, with more outlay of money initially, than doing it this way, and its a gamble as far as what its going to need in $ to get it going good, but its a learning experience for me as well and if i do it right and dont cut corners then it hopefully will work out ok. if everything was quick and easy with no challenges where would the fun be in that? :banghead:

[tunahead72 2,424]

Tearing into a K241, and describing the fun for those of us with "limited knowledge"? Thanks Martin, I'll be watching for sure!

Good luck, have fun, and don't worry if it turns out to be "quick and easy with no challenges", we can all use a break every once in a while. :banghead:

[shorts 182]

well Scott'c m&g makes the second time that we have been at the same place and time and I didn't introduce myself, sorry about that, anyhow about the exhaust valve, lots of pb blaster and as soon as you can get it to lift off of the seat, grab the head of the valve with some channelocks and start turning it while you pry on the bottom of the valvestem, steady even pressure, go easy and it will start to move, if it sticks open tap lightly on it while turning it, clean the large chunks of carbon off the block between the valves and put the head back on with the old headgasket to see if it has enough compression th start. disassemble the carb, at least get the floatbowl and float apart and soak the body/casting in vinegar for a couple of hours to loosen up the majority of growth that is in it, then completely disassemble it and clean it thouroly with a soak in carb cleaner and compressed air. If you want more info or a hand pm me, I'll be in the quad cities for the weekend and have a flexible return schedule.

[tunahead72 2,424]

disassemble the carb, at least get the floatbowl and float apart and soak the body/casting in vinegar for a couple of hours to loosen up the majority of growth that is in it, then completely disassemble it and clean it thouroly with a soak in carb cleaner and compressed air.

Hope you guys don't mind a question or two from the audience....

Since vinegar is a mild acid, is it necessary to neutralize it after soaking the carb, like in a mix of baking soda and water? Or does it matter?

[Martin 2,132]

well Scott'c m&g makes the second time that we have been at the same place and time and I didn't introduce myself, sorry about that, anyhow about the exhaust valve, lots of pb blaster and as soon as you can get it to lift off of the seat, grab the head of the valve with some channelocks and start turning it while you pry on the bottom of the valvestem, steady even pressure, go easy and it will start to move, if it sticks open tap lightly on it while turning it, clean the large chunks of carbon off the block between the valves and put the head back on with the old headgasket to see if it has enough compression th start. disassemble the carb, at least get the floatbowl and float apart and soak the body/casting in vinegar for a couple of hours to loosen up the majority of growth that is in it, then completely disassemble it and clean it thouroly with a soak in carb cleaner and compressed air. If you want more info or a hand pm me, I'll be in the quad cities for the weekend and have a flexible return schedule.

thanks for the offer and the info, paul. i remember we talked a little with steve (stevasaurus) and somebody else at kellys show on the sunday after tearing down the show area, so weve met, it wasnt for long, but its hard to get to chat with everybody, time goes so quick, then its over till next time.

i will mess around with the engine this weekend if i have time, the carb will be getting a good soaking, we have ultrasonic cleaners at work and i will be throwing the carb in one, hope that its not too corroded already.

hope to have it back together and running soon.....

[Martin 2,132]

disassemble the carb, at least get the floatbowl and float apart and soak the body/casting in vinegar for a couple of hours to loosen up the majority of growth that is in it, then completely disassemble it and clean it thouroly with a soak in carb cleaner and compressed air.

Hope you guys don't mind a question or two from the audience....

Since vinegar is a mild acid, is it necessary to neutralize it after soaking the carb, like in a mix of baking soda and water? Or does it matter?

well ive never used the vinegar method...... paul, or anybody else does this method help to clean without too much erosion of the carb?

the ultrasonic cleaning method for me is probably going to help the most, i dont really want to risk eating the carb any more than necessary.

[312Hydro 474]

Great thread, Martin! I always am amazed when I read about these motors starting back up after so many years sitting around. My luck would be getting a bad bore,piston,crank ,you name it! Time to grab the popcorn, I'm in!

[Martin 2,132]

Great thread, Martin! I always am amazed when I read about these motors starting back up after so many years sitting around. My luck would be getting a bad bore,piston,crank ,you name it! Time to grab the popcorn, I'm in!

well at the risk of sounding pessimistic, its not running yet........

BUT, im optimistic that one day soon it will......

hopefully it will mean another early k series lives to run another day....

[shorts 182]

vinegar is an old time trick that I was learned working on marine engines, it's also a hail mary kind of repair, but after looking at the amount of corosion and ''marine type growth" it's worth a try for the majority of us that don't have access to the high tech cleaning methods that Martin does, ''ultrasonic cleaners are not standard equipment in most home shops or mechanic shops.

Cleaning carb and fuel system parts with ultrasound is probably the ultimate method, warm soapy water and high frequengy, it doesn't get any better.

as far as the vinegar soak, the couple of hours time limit and then carb cleaner and compressed air are key players, a couple of hours doesn't mean 3 days or overnight it means a couple 2 or 3 hours in vinegar, blow it out as you finish disassembling the carb and then into carb cleaner for a good soaking (overnight or 3 days and then blow out with comp air.

As far as carb cleaners go,most are solvent based, but their used to be cold soak cleaners that were more like paint rremover that after soaking you rinsed with hot soapy water and then air.

We all know about assume, and it gets me in trouble when I say to clean parts for inspection and or assembly I mean clean like the dishes, you wash your hands before you handle the parts and they are still clean when you are done inspecting/assembling the parts, professional engine techs and refinishing techs know what clean is and that the end results of their labor depends on clean parts.

[Martin 2,132]

well ive progressed a little over the last day or two. first i tackled the carb. took it to work and left it in a paint strip tank for 6-8 hours. its a thin watery type liquid thats deadly on paint and i guess anything other than metals. was going to ultrasonic tank it but we were running some important job in the tanks and the boss didnt want me crapping them all up. the stripper took care of all the gunk and grime and im sure loosened up alot of dried out gas and whatever else is inside that thing. next i gave it a good rinse with water, to neutralize the chemical stripper. came out much cleaner than going in. then bead blasted to liven up the dulled off surface from the stripper. looking good. the stripper loosened the siezed throttle shaft enough to work it loose. took out (broke off) the brass pain in the ass throttle plate screws. the plate came out and i could turn the shaft enough to work on the peened over ends of the screws and screwed them out easy!!!!! shaft out, bead blasted what was left and took it home and threw it in the carb cleaner for a couple hours to make sure i got everything......looks nice and clean inside and out now....

did a little more on the engine tonight took the starter gen and tins off, flywheel pulley and screen and broke two of the screen/pulley screws at the same time. guess im needing more screws to drill out..... (just for the practice)

nice lot of crap inside the blower housing.

gave it a bit of a clean up and tomorrow will work on that stupid exhaust valve, put a new kit in the carb and hopefully get it a bit closer to seeing what it runs like......

[tunahead72 2,424]

nice lot of crap inside the blower housing.

So, now that it's clean(er), what the heck WAS that stuff? :thumbs2:

[Kelly 1,029]

Looks like dried oil.

[Martin 2,132]

that junk in there was oil, dirt and and most of the common junk that builds up over the years. i thought it might have been some sort of home for little critters, but it was all solid stuff, no surprises inside.

[Martin 2,132]

well, i tore it apart and got the exhaust valve loose. also measured the rod/crank clearances, cam end play and gave the inside a bit of a scrub.

the valve involved a lot of careful working to get it loose. gave the stem a good polish up with some emery and now its nice and smooth in the guide. did the intake as well. cleaned up the seats with some compound and installed the valves.

as you can see in the above pic bore has a score or two. hope thats not going to be a problem, time will tell.......

on to the rod big end. took of the cap and immediately saw a score on the cap. the journal had a small nick in it so i polished the high spots off it so hopefully it wont cause any more damage. engine looks like it hasnt done much work since it was rebuilt some time ago. pity about the score in the bore and the rod journal....

plastigaged the rod/crank journal and came up with .002". still under wear limit of .0025".

cleaned up the inside and the oil pan, got some oil in there to lube it up a little and started getting it back together.....

before i spend any more money or make it look pretty i want to see if its a good runner as is, i didnt use any new gaskets, just the undamaged ones that were on it and some ultra black rtv. sprayed the head gasket with some silver and used it too. most of what i spent so far was in the carb, $8 for the rebuild kit and nearly $5 for the brass screws for the throttle plate (had to buy 100).

still waiting for brass throttle screws to get here, then get the carb back together, and finish up some minor stuff and we will see if it goes. hooked up some power and the starter/gen works and it turns over nice. feels like its got some compression, also put my hand over the intake and it almost sucked my hand in there.

really want to hear this thing run now.......

[tunahead72 2,424]

Martin,

You mentioned the 020 piston ... is the piston actually marked that way, or are you going by the 020 that I see stamped into the block in this photo?

You may have already said (in which case I apologize), have you measured the piston and bore yet yourself?

Thanks!

[Martin 2,132]

Martin,

You mentioned the 020 piston ... is the piston actually marked that way, or are you going by the 020 that I see stamped into the block in this photo?

You may have already said (in which case I apologize), have you measured the piston and bore yet yourself?

Thanks!

the piston is marked .020 as well. i didnt worry about measuring the bore, i figure its .020 over std.

the piston in the 1054's k241 is marked the same way, but not on the block's head surface like this one.

[Projekt B-60 0]

Curious... You mentioned "cracked" at the beginning of this discussion. Are K-series susceptible to cracking and if so, where specifically?

I, too, have a stubborn threaded exhaust pipe in the block. I noticed your method for using a punch to collapse the pipe. Is there any risk to the engine-block when performing this procedure? For example, I imagine you really have to hit the punch with significant force to get the pipe to collapse like that. Can that hammering-force have any negative effect on the block and possibly CAUSE a crack?

Thanks, and good luck with your motor!

[Martin 2,132]

Curious... You mentioned "cracked" at the beginning of this discussion. Are K-series susceptible to cracking and if so, where specifically?

I, too, have a stubborn threaded exhaust pipe in the block. I noticed your method for using a punch to collapse the pipe. Is there any risk to the engine-block when performing this procedure? For example, I imagine you really have to hit the punch with significant force to get the pipe to collapse like that. Can that hammering-force have any negative effect on the block and possibly CAUSE a crack?

Thanks, and good luck with your motor!

ive never had to deal with a crack myself. but im sure if a rod went or there was an overheating issue, it could be a possibility. ive read posts on here where tractors have been picked up and cracked blocks have been discovered. between the fins, exhaust mounting, lower bore, back of block from a rod, are some. i dont think its a common thing though. still not enough experience with these engines to know for sure.

as far as the exhaust pipe goes, i think you would be surprised how easy that pipe will collapse. never had one that didnt collapse easy with just a few mild taps with a hammer and chisel. the smaller pipe on the small block kohlers could be a little harder to collapse due to the smaller amount of space in there for the pipe to go, but im sure it would be achievable.

this is the only way that i remove them, i dont think it would cause any stress on the block, once you do one this way, im sure you will understand why. the pipe is soft. just doesnt put any pressure on the surrounding port area. twisting on the pipe with a pipe wrench, on the other hand can have disastrous results, and it wears you out!!!!!! :thumbs2:

[Martin 2,132]

well it runs!

and not too bad either. does blow a slight amount of smoke but only when throttling up quick. really happy that it turned out good for this one. this is definitely the worst that i had to start with, and probably runs the best.....no knocking either!!!

i decided rather than wait for the carb to be back together, that i would use the 1057 as a donor and then decided what about just swapping the engine out and testing it on the 1057? not much work to pull one and bolt the other in. didnt have to mess with a makeshift gas tank and electrical tomfoolery either.

well heres some pics and a couple vids of it running......some might notice oil on the right side of the engine while running. was a bit sloppy when putting oil in .

heres the donor tractor.......everything runs good on this so it was easy to just swap out the engines and a few parts......

engines together on my small cart. this thing has had a few small blocks on it in the past (chevy kind) so how about a couple big blocks! (kohlers that is) this thing makes it real easy to move them around. i also like to use the engine crane even for these things, helps the old back have a rest.........

test engine swapped out and waiting for a few parts...

heres it running.......

I couldnt be happier for what i have in it and i guess we will see what happens with the smoke situation in the future, i still need to mess around a little with it, drops spark every now and again (old coil and condenser maybe) and need to check the timing, just set points at 020 and thats it, battery not charging either, battery was a little low when i started the 1057 this morning, before the operation. the starter/generator looks like its off something else, doesnt have the screw holes to mount the regulator, it was a yellow color in the past and the id tag is sideways. i think its roughly the same otherwise.. heres what it looks like maybe somebody knows what it was used on originally....

[Indy w h 5]

Glad ya got it going Martin !!!

Indy

[stevasaurus 22,764]

Great thread mate. and the pictures are fantastic. Thanks Martin...got my first small engine tear down this winter...this will help tons. :banghead:

[tunahead72 2,424]

Well done, Martin, sounds very nice! And quickly, too.

You might get lucky with the little bit of smoke you're seeing. Since the engine's been sitting for a while, especially outside, I suppose it's possible the rings just aren't quite seating properly yet, maybe a little bit of carbon or other "stuff" still trapped inside. You'll know more as you let it run a bit, but you might consider treating this as a newly rebuilt motor for now, and change the oil relatively soon, maybe after 4 or 5 hours of running, and see what happens.

Just a thought.

Did you adjust the valves properly while you were at it?

[Martin 2,132]

Well done, Martin, sounds very nice! And quickly, too.

You might get lucky with the little bit of smoke you're seeing. Since the engine's been sitting for a while, especially outside, I suppose it's possible the rings just aren't quite seating properly yet, maybe a little bit of carbon or other "stuff" still trapped inside. You'll know more as you let it run a bit, but you might consider treating this as a newly rebuilt motor for now, and change the oil relatively soon, maybe after 4 or 5 hours of running, and see what happens.

Just a thought.

Did you adjust the valves properly while you were at it?

thanks,

yep, valves adjusted. was easier than doing the ones on my 1054 (you remember THAT one, dont you? ......the carb was still installed and engine was on tractor so i had to get through the grill opening).

on this one i had it laying down on my outside bench work bench ( picnic bench outside the garage-dont tell my wife!!) and could sit there and take my time. easy.

as far as the smoke, its a non issue if the engines not throttled up rapidly, i usually set the throttle where i want it and let it go at that. i noticed no smoke at all when the governor compensated while using it. time will tell after some hours on it.

oil will be done soon, im sure theres some floaties in there already........