I am planning on repowering my 20" Grady walk- around with between 150 and 200 hp Evinrude or Johnson. Can't afford a new one (not on school teacher pay) so will be looking at used older models. Which years should I avoid due to service or known problems? Which would be your choice? I realize that maintenance on any motor is crucial, but just wanted some insight into perhaps "good ideas," but "bad engineering" designs from Johnson/evinrude. Which years to stay away from? Thanks.