K-301, what to do ?
 

greetings, i am tryi.g to figure this out...i knew my recently purchased 1250 would need an engine overhaul and was planning on doing it this spring, as it does burn some oil.However, it does surge and i cant adjust it out, neither govener or carb, and it stumbles some. i also then noticed that there is a leak in the headgasket on front side of motor. i was thinking/hoping that perhaps this is what is making it lean, but after plug check it doesnt seem so.although it does make alot of carbon with oil burn..is it worth throwing on a new head gasket, sand flat, and clean?? or could i make it through the winter plowing, and do EVERYTHING with rebuild?? suppose i should pull carb off and clean thoroughly what else could be making it surge so? thanks fellas, any imput would be great...

I'd personally pull it out now and rebuild it.

I would agree, Pull it and rebuild it now. JMHO
good luck keep us posted.

I hate to tell ya,but I agree also. I would pull it and overhaul it now. It might make it through the winter,but if it breaks a rod it could and probably would ruin the block. My 1200 needs rebuilding this winter,I have my 1211 to use to plow with so the 1200 will have the winter off. I limped my 1200 for one last mow this fall,but don't trust it for using all winter.

so i have made an interesting discovery, after pulling the head and carb off an explanation of things has become evident...a screw out of the throttle plate at some point became loose, and fell off, was taken into the intake and through the valve where it was eaten by a few combustion cycles..a few prints of the actual screw complete with threads are imprinted on the top of piston and bottom of head!!! no scoring in the cylinder and the gasket wasnt bad, but im sure the foriegn material is what helped to blow it out..lots of carbon, original std piston...thanks guys

good news.

So im getting to that point (really hate too as it starts and runs like a top) but i need to rebuild the 12horse, she does burn oil and i cant just wait for her to fail..i am hoping to do some minor performance upgrades, sort of a "kirk style" k301..port and polish intake runners, bore carb, handwork everything, mill head some. Cant do too much as it will be used "daily" for mowing/plow duty..so pump gas and need to build longevity (no unlimited budget either, unfortunately)..my question for the experts is; i cant decide where or what parts to do?? I mean depending on measurements as far as motor wear and what not, but what i mean is i always heard kohler rods were a weak link?? So is there anything else avail without spending big BIG $?? So what do you guys run, and from where? pistons, rods, rods with bearings, ebay kits, parts from different motors?? Any help is greatly appreciated...
Thankyou
Mike

Many of these engines have run for 20 or 30 years with original parts. I have no idea how many hours, but way more than I'll ever put on them while I'm alive. My thought is go back with stock parts. "souping" up a K engine for grass cutting seems like a waste. Pulling maybe, but not routine work.

I bought a rebuild kit off ebay. All the parts fit fine. I've read from others on this forum that they've had good experience with these kits.

I agree w/Sawdustdad, Forget the hotrod stuff and go with a good quality stock rebuild, sit back and enjoy the heck out of your cub for the next 20 years or so.

By all means do the carbon cleanup and head resurface as part of an overall maintenance plan as Kohler recommends.

Good Luck!

Thanks fellas, im definitely not building it for 300+', shes a worker!!! gonna be stock stroke and ignition, but having been around some old flathead fords, and having some friends who build huge cubic inch 15.1 full alcohol pulling motors,(and my 383) i cant help it!! i am just going to do some minor things to make her "breathe" better..i just want a bulletproof rotating assembly for the buck. I agree on the kohler parts lasting along time, but theyre not cheap either!! And most of the kits on ebay that ive seen arent entirely genuine kohler..? Gasket and tune up side maybe, but rods seem to be different makers or price goes WAY up..gonna be ALOTof sanding and polishing, and alot of spin balancing. Clean up intake (have you looked in there, mine is like slag city) things of that nature.I mean theres like 3 styles of pistons right? Which are the prefered, the last??Just a little head and valve work, no crazy cam, no high octane, good starter, good performer, good laster..just a little better..so any combinations, things or parts anyone has tried and trued, please im always looking to learn about something...this isnt a small block chevy..
Thanks:biggrin2:
Mike

Just get a regular kit off E-bay. Here's a link to the one Sawdust used. I ordered one today for my engine build........ E-bay.
I just called my order in. Guys name is Kevin. Very professional, and easy to deal with.

Skip the polishing and balancing. It's a worker not a puller. On what a 2.5" run from the carb to the cylinder...... not going to really do much for it at 3600 RPM on pump gas with stock parts. Leave the "frilly" builds for the "custom" engines. Spend your time getting the machine work done right and putting the engine together, clean and correctly. You sound like you want to learn, start at the beginning, with the basics. :beerchug:

My only complaint about those ebay kits (and I've bought two) is that the points they send are wrong for these engines. And in one kit, the exhaust valve was wrong. (there are two sizes I understand).

:biggrin2: On any K-series I rebuild I use only Kohler parts. But a cheap Buddy of mine wanted his K-301 done and would not spring for OEM parts, so I used the E-Bay kit, +.010 piston and a -.020 rod, the crank had already been turned to -.010. this engine is in a CC127, he used it all spring and summer to mow 2 acres and this winter to plow snow. And is very satisflied with it, On my K-321 rebuild, all OEM parts,with all the necessary maching, +.010 bore and -,010 crank and a 3 angle vavle grind. The only thing the was moded was the cam, I sent it to David Kirk for a regrind, same lift but more duration. As for the port and polish, just clean up the rough casting edges. As mine has an heat insulator block between the carb and the block I did port match the insulator. the only thing I wish I had done was to have the rod machined for bearings. If that K-301 has grenade gears, throw them away. :American Flag 1:

Thankyou gentleman..nice to know about those kits SDD..i assume you are a woodworker?? Just finished an old qsawn oak desk for the living room, glad to have my shop back!! Anyways, Dbuck thats good info, i do appreciate it!! How do you like that cam? I need a broad torque curve, and heard those take from idle and low t, with results only at wot?? Just what ive heard, but you know first hand..? Im not a highschool kid looking for more speed, i just like to take years and years of accumilated data (you smart fellas) and make things better..i have a stainless driveshaft in her with the 2 ragjoints per end, an alluminum 2pc carrier on the bench that i got for free, rebuilding a 50" deck with gt spindles, cradle mod, and various other little things ive done..gauges, lights, flashers, wiring harness, (body work and paint this spring) etc..thats all i meant..which style pistons did you guys order? Or does it even matter, or vary in those kits? Dbuck, you would machine OEM rods for bearing inserts?? Clevite? I guess alot will depend on wear and budget, but just like to get ducks in a row...thankyou guys, hope its warm where youre at, because its CCCCOOOLLLLLDDDD here!!
Thanks
Mike

P.S JMech, i have been watching your thread about the ported pump in your 129...learned alot about this old cub from you..hoping someday (budget permitting) to find a ported pump also and put dual hydraulics in her..hope the uptick in prices doesnt hurt us too bad!!

She aint much, but shes mine and i love her!!:biggrin2:

You have a nice QL!

Nice cub! I really like the rear weights. It's a nice tractor. I admire your desire to do things "better than new" and will follow your progress. And, yes, a lifelong woodworker--mostly furniture-tall case clocks, desks, etc. I'll post a couple pics in an album on my personal page if you are interested.

-Frank

Nice looking quiet line!:beer2:

:biggrin2: On the cam you are correct. I have my governor set at 4000rpms but only run it at 3800 rpms on my tach, that way I stay in the power band. But it has been stated that the cam re-grind adds about 3 more HP and 2 ft lbs torque on the top side, never seen a dyno sheet to prove this. Yes, Clevite 77, PN: CB278/Federal Mogul PN: FB 9885CP up to -.030. The only difference is the locking tab location. Another thing I do is, the eyebrow area in front of the valves towards the piston. I radius the sharp edge for a smoother flow. I also tulip the valve head, by radiusing the sharp edge under the valve seat edge on the stem side, this is also for smoother flow. Good luck with your endevers. :American Flag 1:

I am just amazed at that machine...always starts super easy (well except once the bendix didnt kick out, little raps with wood handle screwdriver action) runs GREAT after taking head off, cleaning, rebuild carb, other minor reversals of p.o's handiwork...pushes an UNBELIEVABLE amount of snow, easy to work on, and i could go on and on...best 300 i ever spent...far cry from the '74 case 220 we have, even though that was free from my grandpa..anyways, thanks alot guys...absolutely SDD, i would like to see your work!! I found those solid chunks of steel in a local boneyard (heavy as hell) and just did alot of welding..i actually have three but havent even had to use the 3rd..Thanks again for the info DBUCK, and that part#, all that is REALLY helpful..heres some rearend braces i made and put on a couple weekends ago, when i did the lug studs..didnt know they made em, just didnt like the fact there was only 4, 3/8" bolts holding the rearend on!! Im kinda dumb like that really...but thanks again, anything to catch, look for or info is welcome and appreciated
Thanks
Mike

:biggrin2: MJS, You are Welcome. Glad I could provide a little info. :American Flag 1:

The parts gathering has begun, soon as i know this snow stuff is over the 12 is getting pulled...I have a question; i believe that the 12hp k series came with #26 carb, correct?? Does anyone know the part # and best place to purchase the throttle shaft rebuild kit?? Mine has the extra slop in it and i thought there was either an enlarged throttle shaft that it could be drilled out to fit or a type of bushing kit available??? Any info greatly appreciated..
Thanks

carb
 

Hello. call Lakota Racing they have shafts and bushings. Mike

You can get a bushing for the throttle shaft at a hardware store.
The Servalite part number is: ST814-2


Size is 7/16"x1/4"x1/16"

also the butterfly screw size is 3-48 x 7/32"
A 3-48 x 1/4" works also

Good info!:IH Trusted Hand:

Thanks fellas...yes i had my go around with the butterfly screws already..if you read the beginning of this thread it talks about how when i first bought the tractor it was running lean and the head gasket was leaking..i just needed to get it through winter for plow duty...when i pulled the head i found the series of events; screw from throttle butterfly came out and got eaten, blew out gasket, plate hanging up in venturi bore..glad it was brass...i dont know how long p.o had it that way but i dont think the tractor was run much, but i put in new stainless ones, loctited(red) and nutted on the back...couldnt find a way to peen them over, or brass ones..but this throttle shaft has the 30+yr slop in it, and as im about to pull motor for rebuild i would like to snug it up..so these bushings; just drill out to?? And then press in bushing, and then put the shaft in?? I thought there was an oversized shaft available?? I do like the idea and price of the hardware store bushing though..does everyone agree that the "ebay" (you know what i mean) kits are a good buy?? I would really like to do the "new style" piston and rod, and machine for bearing inserts as dbuck suggested, but if those kits are real good, im all about saving some money....thanks
Mike

You can get brass screws in a pack of 100 from McMaster Carr for a couple bucks. Then you never need any more, and probably about the came cost as your stainless ones. The nuts are a bad idea. I'd take them out, and grab the threads with some vice grips and smash them.

No reason for bearing inserts unless your going to be running the motor really fast. The E-bay kits are being used by several member on here. Most important part is the machine work. Doesn't matter how many $$ you spend if the block isn't prepped correctly.

The Servalite bushings drive right into the bore. (AFAIK, all the carbs had a larger diameter hole at the top of the carb. I'm not sure if it was for a seal, or future use for a bushing.... or if all the carbs had it.) If you need a new throttle shaft...... check prices. It may be just as cheap to buy a new/another carb.

Thats good to hear, thanks...yeah this is a good shop, trust me:biggrin2:...i am thankful theyre letting me bring my little air cooled single popper in there!! I will check into those bushings..no shaft is ok, actually i probably wouldnt even mess with it, but im thinking might as well snug her up...i was debating on the butterfly screws also, i have alot of access to stainless hardware, not so much to brass, and i was in a hurry as i needed to plow with it...they did hold good, but i will check with mccarr (have the big book downstairs)...
Thanks

:Morning: I would use brass screws. If I remember correctly those screws are 3-48's. Any good hardware store ought to have them, along with Hillman bushing # 58087. :American Flag 1: