I bought the mercury racing test boat with very minimal testing I ran 99 with a set of 17.25 34s 18rake and 102 with a set of 17.5 37s 18rake. the faster run was not with my own props so I'm looking to buy a set

What RPMs were those speeds achieved at? Seems like you should be running faster with that tall of a pitch....

Are you able to run those 34s to redline?

about 5350 rpm with the 37s. Not even sure where the redline is. 5500 ? redlined the 34s

34pitch , 17" dia , 15 rake Mercury 5 blades
Got that from a member here when I was looking at that boat. He had a newer 39 with 700's and six's

I have 17.25 X 35 5 blade herrings with 700's and NXT's.

We ran 17 x 34's. Tried 17 x 35's lost one mph and had to trim the **** out of it to get any speed. 17 x 34 was the sweet spot for ours. 2011 700 w/ 6's

Have 42 w/1100's running 17.5 x 35 @ 6400 = 120 mph. Definitely a Hot Rod Lincoln but the 39 is the Corvette. Both rock!

Gary

My boat has no cabin so must b a little lighter.

also do 39 topguns require much trim ? ive got more experience in a 42 fountain with 700s and a 46 outerlimits with 1200 both boats take no trim just ran the drives flat

I'm running Arnesons with 18's, and regardless of drive position and trim tabs, I get on plane 4 to 6 seconds, on average.