Find the leak on the Kawasaki FH and fix it. If it can’t be fixed and is a small leak, then keep oil topped off and run it. Lots of small engines leak oil. You don’t do an engine swap over a oil leak, unless it is gushing out.My FH641v Kawasaki is leaking oil. I have access to a new old stock FR691v. Will the FR691v fit on the Ferris 1500z?