A friend and fishing partner has a 2005 tr21x Triton with a 2005 225pro xs that he is having issues with.
*As boat reaches 5000 rpms + it backs down to 4900 then goes back to 5000. It will not exceed 5000 rpms. You can feel it hit a "wall" so to speak. It ran fine last fall, exceeding 5600 rpms with ease. The only thing my friend did before we took it out this spring was change the fuel filter and added Mercury fuel conditioner/cleaner(quickleen?).
*The local Mercury dealer has run Engine tuner through the motor, changed the plugs(#6 was fouled more than the rest), replaced leaking injector o-rings,ran compression test, hooked up to computer, and had us swap out the coil drivers on the back of the motor. We have been to the River 3 times hoping his mechanic had figured it out. This is getting frustrating.
Would doing a diagnostic on the motor show possible problems at the 5000 rpm level? The Mechanic said he can't spot problems that occur at that range, only at low rpms?
Any suggestions guys? This boat hauled butt last year, but now we get 59mph at 5000 rpms!! ser#1B160414 26p Tempest plus prop(medium load in boat)