Merc Spitfire...

[Kyle Posterick]

Originally Posted by Knot Tellin

Did they have the same diameter? The WOT should have decreased. Below is from the mercury website.

If you’re upgrading from a three-blade propeller to a four-blade propeller, remember that many four-blade propellers generally turn 50 to 100 RPM less than a three-blade propeller with the same pitch.

Mercury Reduced the diameter slightly to keep the RPM's up.

[Knot Tellin]

Kyle - I was thinking of moving my motor up one hole and to see if it would help. I think you may have convinced me to give it a try.

[Kyle Posterick]

Do it, if the motor wont blow out on takeoff and reasonable turns keep going up, its not hard to do with a cherry picker...