Need prop advice badly

[GLASS75]

Im kinda new to outboards and need help. I have got a 1995 Blazer vx-125 with a 1996 evinrude 115 with a prop 12 3/4x19. It is a terd out of the hole and when it finally planes , i trim up but it wont pick the bow up and starts slippin and im only gettin maybe 38-40 mph. What size prop, do i need a jack plate? What size jack plate and set back? Any help would be greatly appreciated.

 

[Joe_Navy]

Re: Need prop advice badly

I need more information from you in order to tell you what kind of prop you need. I need boat length, W.O.T rpm range(in your owner's manual), Your boats dry weight(on a plate mounted to the boat), what you have in the boat and how many people aboard?

You pitch needs to be reduced.

The rule:

Adding 1 inch of propeller pitch will reduce WOT rpm by 150-200
subtracting 1 inch will increase WOT rpm by 150-200

 

[GLASS75]

Re: Need prop advice badly

The boat is 17 ft. I just got the boat but have no idea what w.ot. should be. I also didnt find a dry weight of boat anywhere. I usually dont have much gear but around 650 lbs. with me and other riders and gear. Thanks

 

[Silvertip]

Re: Need prop advice badly

The WOT range for that engine is 5000 - 5500 but that's what the manufacturer recommends. The RPM that's important is what you actually see on your tach at WOT with the current prop. Without that we have no idea what you need -- but we could guess. But before you run out and buy a prop or jack plate make sure the engine is properly tuned and delivering full power. Also make sure the butterflies in the carbs are perfectly horizontal in the carb bores at WOT. In other words -- make sure the throttle is going wide open. I suspect you have an engine issue. I run a 17 foot boat with a 75 HP Merc and a 19P prop. It pops out of the hole and runs the same speed as yours with a 2.33 gearset whereas yours has a 2.0 as I remember. Make sure your engine is running right. Start with a set of plugs and make sure the AV plate is at least flush with or slightly above the bottom of the hull.