Help with Club Tractor

[kenfisher 0]

Hi Folks, I'm a brand new member so if I go astray with any forum rules in this post please let me know.  I have a problem with a C160 8spd with a Kohler K341s motor and I'm hoping you all can help - this post might get a touch long but any advice will be greatly appreciated.

 

I belong to an astronomy club that owns a couple acres of land which I maintain and the above tractor is our sole mower.  While mowing rather tall grass last weekend, the motor started knocking so I eased off a bit and took smaller cuts, knocking quickly resumed and then smoke started pouring out the right side of the motor.  About 5 years we replaced the head and gasket and it was a similar situation so I figured I may have blown the gasket and/or warped the head.  I pulled the head off yesterday.  Gasket looks almost new (no breaks, cracks, burns), bottom of head looks pretty good although I can see some minor scorching from the side where the smoke was coming from.  Top of the cylinder looks great as do the cylinder walls - no burning, scratching, cracks, etc.  Both valves are in the up position.  The tractor was not low on or out of oil.

 

I have very little mechanical background.  My first thought was to replace the head and head gasket and see what happens but that loud knocking of the engine this time (did not happen 5 years ago) has me concerned that there may be more of a problem.  So before doing anything, I was hoping I could get some advice or diagnosis here.  I am happy to provide any additional information you might need.  I'm also wondering if there's more than just a head and gasket problem, is it even worth taking this to get rebuilt or might we be better off purchasing another new or used tractor...I'm thinking there would be little problem kicking up something functional in the $1500 price range.  Anyhow, thanks for taking the time to read this.

 

Best,

Ken

[Fordiesel69 233]

Head and gasket is NOT the problem.  It is more than likely time for a crank & rod.  Put piston to the top and try to wiggle it with your fingers.  If it is loose, time for a rebuild.

[can whlvr 991]

I agree,if shes nocking loud then its a very good chance the rod is going,i would tear it down and check her out before running her anymore,if you havnt destroyed the crank it may be salvageable,shes getting old so a rebuild may be in order,but remember that done properly it will last another 40 years

[km3h 543]

I have rebuilt three of those engines and it is easy and not expensive. Especially for the service you will get in return.