Kohler K341 struggling since repairs....

[goldeagle 31]

I'm struggling getting my K341 engine on my C-165 running well after some repairs. I had to replace the exhaust valve after a screw came loose and ended up in the head. Which meant taking everything apart and trying to put it together again - and having only had the tractor for a month and never having worked on engines before I was a bit out of my comfort zone! I replaced the carb and all gaskets, starter solenoid (twice), spark plug, and after a few issues have finally managed to get the thing running again.

 

However, it doesn't seem quite right. It doesn't sound right, and it seems to struggle when under load. When I put the PTO on to run a 42" deck, the moment I hit any length of grass, the PTO just stops turning, occasionally with some smoking on the belt. The mower use to cut through any length of grass fine. It is like the engine isn't running fast enough or not enough HP. When I turn the engineer of, I nearly always get a little backfire when it stops.

 

I have checked the deck and greased the zerks, it seems ok to me. Checked belt tension on the mule. I've tried some carb and governer adjustments, and moved the governer spring about, although have struggled a little following the instructions in the engine manual (in particular the carb adjustments). WIthout the PTO on, it seems to run fine at all speeds. Engine does get really really hot though - not sure what normal running temp is on these things but will try and take a measurement.

 

Plan to  change engine oil next week to ensure that is not an issue, use a tacho to try to measure engine speed and maybe have another go at carb adjustments. Any other suggestions for what I could be checking to see if there is an engine or deck issue?

[oliver2-44 9,750]

7 hours ago, goldeagle said:

Which meant taking everything apart and trying to put it together again

 

 I replaced the carb and all gaskets, starter solenoid (twice), spark plug, and after a few issues have finally managed to get the thing running again.
 

Engine does get really really hot though 

Can you give us a better description of what you took apart. Did you jus remove the head and valve, or did you remove the piston and or crankshaft. 
 

Did you replace it with one of the aftermarket ones. Do you have the original carb?

 

if the card is set too lean it can cause it to run hot and have power issues. 

[J854D 137]

If you haven’t already, it would also be a good idea to check/adjust the valve clearance (lash) since you replaced the exhaust valve. That procedure is mapped out in the Kohler engine service manual.       -JD-

[953 nut 55,229]

8 hours ago, oliver2-44 said:

f the card is set too lean it can cause it to run hot and have power issues

The carb adjustment would be the most likely place to start being a new unit. You should also check the ignition points adjustment,  you ignition timing is set by the points gap. If timing is retarded the engine will start OK but be low on power.

16 hours ago, goldeagle said:

the moment I hit any length of grass, the PTO just stops turning, occasionally with some smoking on the belt.

That isn't an engine problem, tighten up the trunnion on the PTO a turn and it should help out.

[Wild Bill 633 846]

When you replaced the exhaust valve, did you check the valve guide, cut the valve seat, lap the valve and check for leaks?

[goldeagle 31]

15 hours ago, oliver2-44 said:

Can you give us a better description of what you took apart. Did you jus remove the head and valve, or did you remove the piston and or crankshaft. 
 

Did you replace it with one of the aftermarket ones. Do you have the original carb?

 

if the card is set too lean it can cause it to run hot and have power issues. 

 

No, I didn't touch the piston or crankshaft. I had to remove the carb and breather plate assy to get to the valves. I removed the valve keepers, removed the exhaust valve and put a new one in. Lapped in the new valve, checked valve/tappet clearance and adjusted so that it was in spec. Put everything back together with new gaskets.

 

I replaced the carb becuase the original was leaking fuel after putting it back together. Despite taking it apart multiple times, checking there was no debris, trying another set of gaskets etc I just couldn't stop it leaking. So bought a new carb - one from isavetractors which I assume is better quality than the cheap chinese ones. I still have the original in a box somewhere.

6 hours ago, Wild Bill 633 said:

When you replaced the exhaust valve, did you check the valve guide, cut the valve seat, lap the valve and check for leaks?

 

I lapped the valve with grinding compound, and then adjusted the valve/tappet clearance. No, I didn't check for leaks, just checked I was getting compression then fired up the engine

 

7 hours ago, 953 nut said:

The carb adjustment would be the most likely place to start being a new unit. You should also check the ignition points adjustment,  you ignition timing is set by the points gap. If timing is retarded the engine will start OK but be low on power.

That isn't an engine problem, tighten up the trunnion on the PTO a turn and it should help out.

 

I will check points and try adjusting the carb again. Will also tighten the trunnion and see if that helps (just looked it up in the manual to work out what ii is!)

[wallfish 17,000]

23 minutes ago, goldeagle said:

Will also tighten the trunnion and see if that helps (just looked it up in the manual to work out what ii is!)

So is the problem with the engine running?

OR, that the belt stops? Tighten that trunion for the PTO to squeeze the bell harder into the clutch plate. That's the issue with the PTO pulley not turning and slipping.

Also a good idea to post some pics of that loop and how it's connected. Snap rings pop loose, pins break, lots of things going on with that linkage

[squonk 41,118]

A lot and I mean a lot of carbs leak at the fuel bowl nut. Then we tighten them some more and they leak worse and bend up the bowl. I would take off the bowl and check straighten the nut sealing area. Then I would coat the surface of the bowl where the nut gasket touches with the UK equivalent of Permatex Aviation sealant. Also coat both side of the nut gasket and the sealing surface on the nut and try the original carb again. Some of those offshore carbs aren't jetted / sized right. 

 

Strange. Last I knew I Save Tractors didn't ship overseas? 

Edited June 17 by squonk