Hello i have a 2003 exmark Lazer z. it has a Kohler 27hp air cooled engine. model # ch740-0007. I blew the motor. it is not fixable. I took to a machine shop and they agreed. it also had high milage about 3700 hours. my question is I found another Kohler motor motor 31hp Aegis EFI Liquid cooled. model # LH775s-0013. It is roughly the same price. It will need a little modifying to put in. But im shure i can handle it. Would this be a good idea or is it not worth the trouble. should i just stick with the original motor. does the efi run better than carburated.