a jack plate will help. watch yer water pressure.

you should be able to look, in good lighting, straight down at your prop looking at the hub and it usually says it there or at the base of one of the blades for your pitch.

You could afford a couple few more hundred rpms I believe the yamaha can go 62k. Check your manual if it says 52k to 62k then go down 1 pitch on your prop and it will give you 2 - 3 hundred more rpms bringing you up to 5800 or so and increase top speed a little. If the manual says 62k max go down 2 pitch you will get about 600 more rpms.

This is if your motor can afford it. check the manual for max rpms.

Bought a 18'cc xpress with a 90 about a month ago(new). it'll go about 37-39 mph according to gps. It came with a 13 1/4x 17 alum prop. I got a ding on it and it seems to be vibrating(shaking), Looking for a ss prop, any suggestions or maybe working the ding out....

Ive got a 22 foot xpress with a 115 4 stroke on it. I top out at about 5400 RPM's and it hits about 44 on the GPS. I have a 19 pitch on the prop. Just bought the motor, so Im going to go down 1, maybe 2 and see if I can get some more speed!... and now that you said that that I dont know about the hole shot. The operating range is in 5,000 to 6,000 RPMs.

i thought downing yer prop pitch makes u git slower holeshot but more top end speed... am i wrong?

I have a 20ft express with the 115 4 stroke yamaha and I had to step down to a 17 prop due to the 19 would not let me get above 4k rpm. I still have my hole shot but I can get up to 57-5800 rpm now.

I got a 17 ft Xpress with a 90 Yamaha and i'm only turning 5000. Can anyone tell me all the stuff i can do to get some more out of it

I have an 1860cc duracraft with a 90 evinrude and thats all im turning is 5000.

When I bought my 16ft cajun special w/70 yamaha 2nd hand I found it sluggish.When I went to a prop shop I brought the ss prop and told him the problem.They let me trade in for new .Check your manual mine said 6k .The new ss prop runs 5800 @35-37mph great hole shot.It has been 2years now very satisfied.Find a good prop shop and invest you won't regret

to pick up rpms, repitch your prop down. they will only move it up or down 2 spots, so do it accordingly to your manual. a jackplate may help with top end also, just be aware of the rpms, and adjust your trim accordingly.

I have an Xpress knockoff (17', side console)with a 90 Merc on a jackplate and I can get 45 mph with one person. I think I am turning about 5600 or so, but don't remember. I don't use it enough to remember. Any baody want to buy a boat? hehehehe

BTW, if you were going in the 40s you wouldn't think it was that slow IMO. 45 is plenty fast enough on the water.

I have a 17ft express sc with a 90 Yamaha 2 stroke it turn sabout 5700rpms maxed out and with just me in it tops out at 48mph on the gps.

I can't believe noone can get this right!?!? Example: you have a 13'' aluminum prop. Your turning so many rpm's you rev limiter is hitting. But you have a great hole shot. Move up to a 15'', or even 17'' stainless prop!! You will loose a little hole shot, but will gain in top end! ALOT!!! I have a 40 Nissan on the 13'6'' Whaler. It came with a 13'' aluminum prop. It got out of the water real fast, but hit the rev limiter(6000rpm) at 36 mph. Changed to a 17'' stainless and got to 45 mph at 5100 rpm's. Totally out of control!!! Couldn't control the boat at all!! Whole thing was out of the water!! except for the lower unit. Had it repitched to a 15. That was the money! Get 42 out of it with just me, no gear, still squirrly, and out of the water, but with gear and kids, it'll cruise at 36 or 37 comfortably and right in the rpm range it's supposed to be at 5100! That's experiance talking, take it to the bank!

Try this site out it's the Prop Wizard. It should tell you what you might need.
Good Luck Hope It helps you

http://www.marineengine.com/parts/prop/prop_wizard.php

My friend, if you are looking for questions to be answered call BAGGY'S PROP SHOP in Houma, LA. My godfather told me about him when I needed my Tempest prop reworked. Evidently this guy is one of the best in the world. A lot of those guys in the powerboat racing use his props. Anyway, he got 8mph more out of that Tempest which is on a 150 Merc-18ft Champion dual console without changing the RPM range b/c it was where it needed to be. I would give him a call, worth the time and excellent work.