Kohler K341 rebuild

[c175inMA 8]

Hi all,

I have a c-161 which is pretty beat-up and i would like to rebuild the engine, the reason being that is smokes on startup and excellerating. Right now it also doesn't have a muffler on it, just a 2in pipe, and i noticed that is spits flames then under full throttle(i recently picked this tractor up and haven't run it more than 20 min). My question is do i need to rebore the cylinder? It doesn't smoke that bad but i need a project anyway and i'm looking to not have to spend an excessive amount of mony on the rebuild. Any tips for doing a rebuild, links to previous threds, and comments would be appreciated. Thanks, Paul

[coldone 35]

My 341 is spitting flames too. Pulled the head, sprayed some lube on the closed exhaust valve, and put the compressor nozzle in the exhaust manifold. Stuffed a rag around the nozzle and gave it a squeeze to pressurize the underside of the valve. I had bubbles all around the seat and valve. Leaking exhaust valve! gonna try lapping it and see if I can get it to seal.

[can whlvr 991]

well in answer to if it needs a bore,it needs to be measured,you can tell if it does sometimes by looking at the cylinder walls,but really it needs to be measured up,the crank journal too,some smoke is normal on start up but not that much,its a 16 hp kohler and very sought after motor,its worth doing it right,bore,grind crank(if it needs it)new rod,piston rings,piston,gasket set,maybe valves,and checking the balance gears and their bearings and stubs they ride on,theres lots of talk whether to get rid of them or not,you have to choose on that issue,i just rebuilt a 12 hp and tossed the balance gears,good luch and keep us informed

[bowtiebutler956 649]

You have my favorite model of Kohler there, I don,t own one yet but I will one day. There was thread very recently on a K341 rebiuld, just look up K341 TLC. The is a place on call This Mans One Stop Shop that will sell you a rebiuld kit that has new piston, rod, valves, gaskets and seals for less than $120. The parts are aftermarket, but they look great, and my K301 is running great with a kit from this place in it. As far as whether or not you need to bore it, you really need the bore to be checked by a machine shop. My machine shop only charges $30 to bore one cylinder, so to me I couldn't see any reason not to, but I don't know what your shop will charge. You are going to run into alot of different opinions on whether or not to keep the balance gears, I left mine out, and I am very happy with my motor. Good Luck, and ask as many questions as you like. I would really like to follow the progress of your engine.

Matt :flags-texas:

[can whlvr 991]

ya prices vary alot on shop costs,it costs me a 150 bucks to measure,bore and turn crank and polish crank shaft ends

[bowtiebutler956 649]

Prices do vary alot, but I didn't have to pay for any polishing. I love polishing, nothing quite like pulling out the old emery cloth and making your crank look like a mirror! I polished my crank first, then when I took the block to the machine shop, I had them mic the crank, and it was perfect. Now I did pay a little more because I had them deck the block $25, resurface the head $25, and grind the valve seats $10. The kit I bought came with new valves, so they didn't have to mess with them.

Matt :flags-texas:

[Hydro 130]

Not sure what you mean by "pretty beat up". Physical appearance is one thing, cylinder bore and tolerance may be something different. My 16 smokes on start up too but it's because of the glut of gas going into that big single cylinder. Remember a straight pipe has no baffles. Maybe just run it for awhile and get used to it.

They aren't making anymore of these engines so it's a keeper no matter what you decide. How much extra for the real McCoy... (Kohler parts) spread over...hundreds of hours? :twocents-02cents:

[c175inMA 8]

Thanks for the comments. I guess i just need to take it apart and see what's worn inside. When i say it's pretty beat up i mean outer appearance. What do you guys think about the flames? Is it too much gas getting through or is it a valve sticking? Never taken anything but a small 6hp techy apart before so this will be a learning experience. I'll keep you guys posted. Thanks

[can whlvr 991]

im pretty sure that because you have no muffler thats why you are seeing flames,dont worry about that,once shes apart and rebuilt you wont need to worry if its a stuck valve or not,which i dought,moat engines shoot flame out the exhaust at some time,you just dont see it usually

[c175inMA 8]

Hi y'all, it's been awile. I got everything apart and took it to the machine shop to see if it needed to be reboard. They said that it was hardly worn and didn't need to be reboard, so i had them hone it and grind the valve seats. I have a few questions however.

1. What is the best way to clean the rust out of the cooling fins? I have a small sandblasting gun and i'm wondering how that would work.

2. What is the best way to paint the engine? Best to put it back together and paint it or tape stuff off and paint it while it's apart?

3. In the picture of the piston below there is a gouge missing. I thought this was a problem but then the new piston also has this. Is it normal?

4. In the pictures below where the cam-shaft goes into the black it lookes like chunks of metal are missing. Is this normal?

5. Will any k-series blower housing work, because mine is rusted out?

[bowtiebutler956 649]

That great that your block didn't need boring. The notch in your piston is there to tell you the direction it is supposed to be facing in the cylinder, but I cant remember which way. Do you remember which way it was facing when you removed it? If not, Im sure someone here will know, or you can find downloads of the manual on the web. The notches in the holes where the cam goes are there so oil can get in there, and they are normal. Also you will see a small oiling hole in the connecting rod, it has to face towards the camshaft, or it won't receive proper lubrication. Your sandblaster should work great on the rusty fins, but don't get any sand in the bearings, and make sure you clean the block very well afterwards. Sand and engines don't go well together! The way you paint it is up to you, but I like to paint the parts separately, after taping off. I'm not sure about the blower housing, but I'm sure someone else here can tell you. Good Luck!

Matt :flags-texas:

[can whlvr 991]

so a few things,i would download the kohler engine rebuild manual,its very useful and has all the info you need,you can sand blast the fins but its a good idea to seal up the engine as best as you can as bowtie bust said,sand and engines dont mix,you can also use a wire wheel on an angle grinder ,i used engine enamel on my engine and i painted mine first then gave her a touch up coat after assembly,just tape off areas that dont get painted like seal surfaces and gasket areas,if you are gonna sand blast you must take out main bearings if you havnt allready

[c175inMA 8]

Thanks guys, i think i'll sandblast and then paint before assembly. I don't remember which way the notch was but i'll look in the manual. I already tried wire-wheeling the engine and it didn't go deep enough. I did already take the bearing out.