I purchased a 3 blade prop last week for my 35 GTR to replace the old worn out power tech 2 blade P10. It was my understanding was the 3 blade would reduce vibration and slightly increase speed. Well $275 later , two trips out and two hours running , I'm not at all impressed.

Old worn out prop.
200 lbs bow deck installed and 2 men 250 ea. my boat ran 19-22mph No plow.

3 Blade GTR Prop.
1st trip out with 200 lbs bow deck installed and 2 men 250 ea. my boat ran 7-8 mph and plowed hard,
2nd. trip out 200 lbs bow deck removed , still 2 men 250 ea. My boat ran 9-11 mph and plowed hard.

I spoke to gator tail rep and it was concluded that my boat was heavy and would likely need to use a 2 blade 12.5 prop.

I spoke to a prodigy rep and they said they would send me a spacer to go behind my prop and that would solve my problem ??? I asked what that was going to do and was told not sure but service said that's all you need and they would mail it out free of charge... still scratching my head...

I guess my question is , has anyone ever experienced anything like this and if so , do you have a responsible answer as to why my boat won't work with a 3 blade prop?

Stock Motor?

Big boat, heavy loads, stock motor = 2blade the way to go.

A fresh big blade is probably what you need.... but it should still probably plane a 2 man load...

How many hours on your heads? Ever been touched?

What are your rpms?
Heavy boat, heavy load, could be too much prop. a 3 blade is harder to turn than a 2 blade of the same pitch.

Some props have thicker blades, more cup, more diameter, and/or higher pitch! All 4 things things affect motor rpms along with boat and the load. If no mods, the 12x10 prop will be better. IMO

Just to info you Signature props has 12.25x10, 11, or 12 your choice $220.
http://hillmarine.com/weedless.html