Originally Posted by nick1
Are the pro series any good for my merc 300 promax?.
You have 2 routes to go down....
1, keep the prop you have 23 or 24 4 blader this should put you up to 6500 6800 rpm and about 72mph but stable especially if you have kids on board. If the motors not getting to that get it to a merc dealer for a check over ( marine nautique ) closest to you I think. The 21s bow will bounce up and down with a lot of fuel and weight at the back, this is why a 4 blader is quite suited for 21 as it will lift the stern a little.
2, buy a 25 raker get the hub changed to fat shaft at prop solutions, get the rig to Neil Holmes and have some lessons on driving it..... 21,300x,25 raker 81 mph but very very flighty.