rmaynard 14,945 #26 Posted January 9, 2014 K161 & K181 share the same piston. The crankshaft (stroke) is different. Not all the same. Some K161's had a smaller piston that measured 2-7/8" (2.875) 2 Share this post Link to post Share on other sites
Fordiesel69 232 #27 Posted January 9, 2014 Per the Kohler K series manual K181/K161 have identical bores. I also checked my K161 generator vs my K181 875 tractor and the pistons were the same. Share this post Link to post Share on other sites
shorts 182 #28 Posted January 9, 2014 Post a picture of the scratch in the bore, is it deep enough to catch your fingernail in it? Also can you catch a fingernail at the top of the cylinder where the top ring stops? Share this post Link to post Share on other sites
rmaynard 14,945 #29 Posted January 9, 2014 The later ones did, but the earlier ones had smaller bores. I refer you to a post from TT. Share this post Link to post Share on other sites
shorts 182 #30 Posted January 9, 2014 You don't have to replace the rod, but they are aluminum alloy construction with integral bearings machined in place. my opinion is if you're replacing the piston and rings you should replace the rod too as it also has lived it's expected life cycle and is old and tired to the point that it might not last long with the increased power of a fresh engine. Like I said your engine and money, my opinion with 50 years of engine experience 2 Share this post Link to post Share on other sites
wheelhorse66 10 #31 Posted January 10, 2014 is the piston supposed to have any movment in it without the rings on the piston,i took the rings off the piston and when i put the piston down the bore it had a little side to side play Share this post Link to post Share on other sites
TT-(Moderator) 1,129 #32 Posted January 10, 2014 I apologize if this topic is helter-skelter, but I just merged four or five topics started by the OP related to the same or similar engine questions. Share this post Link to post Share on other sites
wheelhorse66 10 #33 Posted January 10, 2014 OK sorry bout that new to this rebuilding stuff Share this post Link to post Share on other sites
WH nut 553 #34 Posted January 10, 2014 You really need to get the Kohler manual and do some reading. It will tell you everything you need to know. Then is you have questions we can answer. Share this post Link to post Share on other sites
rmaynard 14,945 #35 Posted January 10, 2014 OK sorry bout that new to this rebuilding stuff PM sent. Share this post Link to post Share on other sites
kudzu3 323 #36 Posted January 10, 2014 Might as well throw my 2cents in. If it were mine and I already had it apart and the condition is as you describe, I'd go ahead and get piston, rings, rod, have the cylinder bored (or at least conditioned), be sure the valves are in good condition, have it all professionally assembled and don't look back. It will last for many years to come. An internet search for parts will turn up many sources. Good luck with it. Share this post Link to post Share on other sites
