11mph with a 50hp

[limulus]

There is something weird going on here. I'm seeing too many posts from guys who swear by their GPS units that their lower HP motors are pushing their twin log boats at incredible speeds. 20+ MPH from a 50 or 75HP motor on 22-24ft boats? Have these motors been modified? I often wonder if something is wrong with my motor which I bought new in 2007. Before I added the waterglide, I could hit 24 MPH but could not hit the 6500 RPM max with anything other than a Turning Point prop. I have tried 6 different props including:
1. original prop that I think was 14x13 (<4500 RPM max)
2. Solas 14x11 (fastest prop 24 MPH. Can't remember RPM but was <6500)
3. Turning Point Hustler 14x11 (ran like a sewing machine...>6500 RPM but slow)
4. TP Hustler 14x13 (also >6000 RPM but did not improve speed)
5. TP Hustler 13.75x15 (can't remember speed and RPM)
6. Black Max 14x13 (current Prop. 23MPH w/o water glide, 19MPH with water glide)
I'm going to put the TP 13.75x15 back on when I get a new hub adapter for it (I lost the original). I have to adjust the water glide, but just never seem to have the time. Last weekend was so bloody damned hot, that I had no desire to do anything.

I have to think that the Mercury 115 4s went to hell when they stopped using the Yamaha heads. They also used a gear ratio of 2.07:1. Now, the ratio is 2.33:1 and someone at Mercury told me that was because they had a lot of high altitude users...WTF?

How hard is it to change a gear in an outboard? Our lake is at 2000ft which is not high altitude, but I swear the new ratio would be better than what I have.