20 HP Nissan Slooow when loaded

[mcutrell]

I have a 20 hp Nissan 4 stroke on a G3 1756 Jon. With just me it will run about 20-22 mph. If i add another passenger it drops to around 10 mph and never completely planes off. I also have a 40hp merc for this boat and it only drops about 2-3 mph with the same loads. Where should i start with getting my nissan to plane off better, prop or hydrofoil? I am willing to sacrifice a little top end to get it to plane off better. It has the stock prop so if that's my best route what prop should i be looking for.

 

[pvanv]

What is your actual model? What does a tach show? Is the jack height correct? You likely need less pitch.

 

[TOHATSU GURU]

Move the engine up on the back of the transom about 1/2 inch. Change your prop pitch by 1" down from whatever you have on it now.

 

[Sea Rider]

Factory motors delivered with a prop are medium pitched ones and under propped for large and heavy applications. If wanting to get the max HP out of that motor install an induction tach, trim motor to run at 90 deg, distribute deck weight evenly, go for a wot spin and report max wot rpm achieved with 2 up. Only then will know how many pitches to drop. Isn't known if in need to drop one or two full pitches down. Only a tach will 100% accurately tell..

Happy Boating