We re-powered a 1989 Mako 210WA with a 2012 175 E-Tech replacing the original Yammi 175.The performance has been much lower than expected. The first prop, Rebel 17" pitch, only produced 4450 RPM and 34 MPH WOT. The engine was raised 1 hole to #3 and a Cyclone 15" installed producing 5050 RPM and 36 MPH WOT. The dealer has not been much help in maximizing performance even though they stated that the optimum RPMs should be 5600 - 5700 for best overall results.
The boat has a dry weight of 2500 lbs. and the 22 year old Yammi managed 4900 and 36 MPH.
Any suggestions as to where we go from here. Is the Viper a viable alternative to try?
04-26-2012 01:23 - edited 04-26-2012 01:24
Those old Makos were solid but heavy boats and need low pitched props to get the engine revs up to the recommended range.
Ask your dealer to check the throttle linkage, control box, and TPS adjustment to make sure that the motor is getting the throttle opened fully, that the boat's fuel system is tested for vacuum restrictions and air leaks, and that the motor is performing as it should by performing the cylinder balance tests. The tachometer accuracy can also be verified at the same time.
Also check the boat hull condition and if the bottom paint is chipped or very rough which can affect boat performance.
It is possible that you may have to go to even a smaller pitch prop for a boat like that if everything checks out OK.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
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