Jesse 4 #1 Posted September 7, 2012 I just bought a 68 Raider 9 the other day. It has a Kohler K181 engine but I think it might need a connecting rod. I was just wondering if anyone has ever had trouble with aftermarket engine parts before I buy anything. Thanks. Share this post Link to post Share on other sites
MarkPalmer 81 #2 Posted September 7, 2012 I never had problems with aftermarket parts from Stens or Rotary up until recently. I have rebuilt 3 K181's over the past several months and it seems like everything, even new parts from Kohler, are measuring undersize- as in new parts measuring even smaller than the old worn parts I am removing! This has included pistons, rods, and valves. Everything now has to be measured carefully and machined accordingly. It's ticking me off these new valve stems, even on new valves right from Kohler, are so undersize- it means either grinding old valves that are on their last legs, or installing and reaming new guides to fit which is a PITA. The last Rotary K181 piston kit I got was so undersize in the standard bore that when test fitted it had so much clearance to the bore (bore measured in spec) as to be comical- of course I didn't run it, and found a good used piston that fit with the right clearance. With what I've been seeing for new K series parts this year, I don't think I'm going to be working on too many more of these engines as to do it right all the machine work is getting too expensive. I hope everyone else is having better luck. -Mark- Share this post Link to post Share on other sites
Jesse 4 #4 Posted September 7, 2012 I never had problems with aftermarket parts from Stens or Rotary up until recently. I have rebuilt 3 K181's over the past several months and it seems like everything, even new parts from Kohler, are measuring undersize- as in new parts measuring even smaller than the old worn parts I am removing! This has included pistons, rods, and valves. Everything now has to be measured carefully and machined accordingly. It's ticking me off these new valve stems, even on new valves right from Kohler, are so undersize- it means either grinding old valves that are on their last legs, or installing and reaming new guides to fit which is a PITA. The last Rotary K181 piston kit I got was so undersize in the standard bore that when test fitted it had so much clearance to the bore (bore measured in spec) as to be comical- of course I didn't run it, and found a good used piston that fit with the right clearance. With what I've been seeing for new K series parts this year, I don't think I'm going to be working on too many more of these engines as to do it right all the machine work is getting too expensive. I hope everyone else is having better luck. -Mark- That's what I was afraid of. Thanks for giving me a heads up...................I hate buying junk. Share this post Link to post Share on other sites
can whlvr 994 #5 Posted September 8, 2012 i buy aftermarket and then the machine shop bores accordingly,and my new rods when checked withplasti gauge were dead on Share this post Link to post Share on other sites