Would like to know specific prop size for yamaha 60 bigfoot or 75 when used on a mac 26M or X. Am Still undecided on engine. All the 4 stroke 75/90, Yamaha, Honda, Suzuki weigh about the same, 370lbs, Suzuki has no convenient dealer in my area. The Evinrude E-tec is intriguing at 50lbs lighter but again the nearest decent dealer is 90 miles. It is about the same cost as the Honda/Yamaha, but longetivity may be questionable. Thanks for owners input on this thorny issue. - Capt Jim
prop size for Yamaha 60 bigfoot or Yamaha 75(26m)
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Matching Prop to Engines
Matching props to engines is a bit of black art mixed with science and is somewhat more difficult with a Macgregor hybrid. I think I have heard 14 X 11 for the Yamaha 60 BF (14 diameter) but don't quote me. Try this site: http://www.macgregor26x.com/ There are many X & M owners wwith various sized engines and they have done extensive testing, do a search on engines or props. Be carefull of your engine selection and perhaps calculate your power to weight ratio for each model so that you get the most HP for the least weight. Even though most new 4 stroke engines are extremely reliable I would still prefer to have reputable service within easy towing proximity, my Honda service/dealer is only one half hour tow. The Yamaha high thrust 60 might be a good choice since it swings a 14" prop, the other ones 75 & 90 also swing a big prop but they are very heavy for the extra horsepower gain. The Honda 50 with a Solas Alcup 4 X 11.8 X 9 is a good combow to consider.
Matching props to engines is a bit of black art mixed with science and is somewhat more difficult with a Macgregor hybrid. I think I have heard 14 X 11 for the Yamaha 60 BF (14 diameter) but don't quote me. Try this site: http://www.macgregor26x.com/ There are many X & M owners wwith various sized engines and they have done extensive testing, do a search on engines or props. Be carefull of your engine selection and perhaps calculate your power to weight ratio for each model so that you get the most HP for the least weight. Even though most new 4 stroke engines are extremely reliable I would still prefer to have reputable service within easy towing proximity, my Honda service/dealer is only one half hour tow. The Yamaha high thrust 60 might be a good choice since it swings a 14" prop, the other ones 75 & 90 also swing a big prop but they are very heavy for the extra horsepower gain. The Honda 50 with a Solas Alcup 4 X 11.8 X 9 is a good combow to consider.
Try This
Capt Jim, Here's how I would figure it out. The engine manufacturer's web site has prop size recommendations for each motor. That will give you the max. outside diameter. Next, you will need the pitch. For the heavy Mac X and M, you will need a low pitch. I recommend a 9 or 10 pitch for this boat. Mine has an 8 and it works fine. Any higher and the engine won't get up to a plane or max rpm. As far as engines go, I choose based on price. You will find that there are only about three manufacturers and they are all comparable. Other factors are things like power tilt, alternator power, long or short shaft, etc.
Capt Jim, Here's how I would figure it out. The engine manufacturer's web site has prop size recommendations for each motor. That will give you the max. outside diameter. Next, you will need the pitch. For the heavy Mac X and M, you will need a low pitch. I recommend a 9 or 10 pitch for this boat. Mine has an 8 and it works fine. Any higher and the engine won't get up to a plane or max rpm. As far as engines go, I choose based on price. You will find that there are only about three manufacturers and they are all comparable. Other factors are things like power tilt, alternator power, long or short shaft, etc.
Yammy or Merc?
I have a Merc bigfoot 60 with a 14 x 10. The perfect match. Formerly I had a Yamaha 70 with a 13-5/8 x 13. Way too much pitch. The Yamaha equivalent of the Bigfoot is called the "High-Thrust". I guess you knew that, but thought I'd clarify it for others?
I have a Merc bigfoot 60 with a 14 x 10. The perfect match. Formerly I had a Yamaha 70 with a 13-5/8 x 13. Way too much pitch. The Yamaha equivalent of the Bigfoot is called the "High-Thrust". I guess you knew that, but thought I'd clarify it for others?
14" x 11 pitch works best
the typical 70/75 and 90hp outboards with a 14" prop seem to do best with an 11 pitch. that is, the 11 pitch will get a standard to heavy loaded Mac X/M to desireable RPMs at WOT. some owners have opted for a 13 pitch which provides an additional 2-3mph at WOT, but at the expense of lowering the RPM's to a state which is less than desireable (i.e. not good for the motor). i say this because (in general) anything less than a 150hp on a boat of this size/weight is an "under powered" boat. so to compensate for the underpower variable, you must allow the motor to reach the max RPM band. generally, an 11 pitch does this and will push the boat to a desired speed as long as the prop has maximum surface area (i.e. big dog ears).
the typical 70/75 and 90hp outboards with a 14" prop seem to do best with an 11 pitch. that is, the 11 pitch will get a standard to heavy loaded Mac X/M to desireable RPMs at WOT. some owners have opted for a 13 pitch which provides an additional 2-3mph at WOT, but at the expense of lowering the RPM's to a state which is less than desireable (i.e. not good for the motor). i say this because (in general) anything less than a 150hp on a boat of this size/weight is an "under powered" boat. so to compensate for the underpower variable, you must allow the motor to reach the max RPM band. generally, an 11 pitch does this and will push the boat to a desired speed as long as the prop has maximum surface area (i.e. big dog ears).
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