Dieselcowboy 210 #1 Posted August 23, 2013 How much different are these engines> Can I take one of each and put all the good parts together and get one to run? Pistons , rods, heads blocks , ect? Share this post Link to post Share on other sites
VinsRJ 723 #2 Posted August 23, 2013 In my experiences there are a number of parts that interchange between these motors... heads/pistons/rods/cranks. Where they get wierd is the ingnition systems, some K90s had that old Bendix ignition which is a POS IMO. Because of that the bearing plates and flywheels will not swap. At the end of the day I believe Kohler did about the same thing as Clinton... rename their motors so they could indicate a higher HP. Both versions of their motors are the same with slight differences... all of which would not add up to a .5hp increase. Kohler: K90 3.5HP / K91 4HP Clinton: 1200/A1200 3.5HP / B1290 4HP Share this post Link to post Share on other sites
specialwheelhorse 174 #3 Posted August 23, 2013 If I'm not completely off my rocker it seems the 90 may have a different head thus perhaps a slightly lower compression ratio and was governed at 3600 and the 91 was governed at 4000. Share this post Link to post Share on other sites
buckrancher 2,695 #4 Posted August 23, 2013 the 90 's head has curved fins and the 91 has straight ( quick way to tell them apart) Brian Share this post Link to post Share on other sites