2002 Yamaha 115 hp F.I. 4-stroke w/72 hours sounds and feels like its not running on all cylinders; WOT yields 4200 rpm and 30 mph max; normally runs 45 mph WOT; no obvious water in fresh gas. What could be some reasons for this?
hello<br /> test the plugs. I have had several with bad spark plugs. to isolate a cylinder while running in the water in gear at idle remove the injector connector and note RPM drop. should be the same for all cylinders. its a quick way to isolate or eliminate a cyl.could be a clooged engine filter.<br /> and is the boat bottom clean?<br /> good luck and post back
Thanks. I'll try and test the plugs. The bottom could be cleaner and might cause some loss of speed, but that shouldn't cause cylinders to cut out, should it?
backer,<br /><br />Do the cylinder drop test as rodbolt suggests. If that OK, your bottom condition can hurt performance far more than you may believe.
