Rollerman 290 #1 Posted September 26, 2009 Recently aquired a Kohler Magnum 20 twin. I also know of a 90 520H with a blown engine. Has anyone here ever worked with a Magnum twin & can give me a heads up? Any input from those in the know or keyboard mechanics appreciated. Share this post Link to post Share on other sites
htopjimmy26 3 #2 Posted September 28, 2009 Well, I have played a little and had a M18 running on my c141 for a little while and I can give you the lowdown on a couple items. 1rst look up your spec number and determine if you have a roller thrust bearing in your motor along with the correct length and size crank snout, chances are that you don't have the thrust bearing as the only 20 hp magnum WH used was in the 420lse=1 year tractor. Magnums twins used Bimetal automotive style bearings, I think that the correct crank should be somewhere around 1-1/8 diameter X 3-25/32 long, I forget the keyway. Once you determine that you don't have a roller thrust bearing engine go shopping for an electric PTO clutch=$200, other than that you may be able to use your Onan engine plate, you are gonna lose all your gauges and have to wire up an ignition switch as Magnums have a magneto ignition and Onans have electric ignition. You should be able to make this swap kinda professonaly if you take your time you can also look at the 418 tractor as is pretty similar to what you are doing, Good luck :scratchead: Share this post Link to post Share on other sites
