Mercury Sportmasters
 

I just put these Mercury Sportmaster lower units on and have tested them 3 times with the same results, Loss of to much speed. I knew I would see some loss but not 5mph. I have no intention of putting more Hp so I think I am going to put the old units back on. One lower has all new bearings with 4 hours and the other is stock with 25 hours. I will sell both lower units with all hardware including new prop hub kits. Everything needed to install these on new or old style Bravo Drives for $ 5500.00 plus shipping. They a re like new no chips and the skegs have not been cut! If interested, PM me for more info.

Racer, are those standard length?

Yep - here is what they look like if you shave them back to the standard length of XRs.

i think he meant -2 shorties versus standard length, not shorty.

Yeah - my bad. I was thinking of the skeg length which at one point Merc talked about shortening. Not sure if they ever did or not. I doubt it since the longer skeg tends to work better on the cats, or at least that was what they reported.

I meant prop shaft dimension.....not skeg length.

yes

Did you run the lowers before you cut them? If so what was the difference before and after. I hate to cut them and not see any gain.

Factory did since it was the first boat. The Merc engineer that helped them do the set up suggested cutting them to the same size as the regular XR lower skeg.

I don't recall what the numbers were, but it ran better and did not impact handling. I can call the factory and see if they remember the actual performance difference.

I just don't to cut them and only see a 1-2 mph difference or no worse, no difference .

Just talked to Wayne Shaldenbrand (owns Sunsation). They saw about 1.5 mph on mine. His opinion was the skeg length is not your issue if you lost 5mph. He guesses your X dimension is not right for the Sportmaster and the whole drive is too low. His opinion was you won't see much improvement by shortening the skeg.

I think your right, have not looked at the dimension of the sport vs standard lower but that makes sense. But they look good :D