21 SteigerCaft, Maiden Voyage -prop question

[cjd]

So i finally got to get the boat on the water for a serious run, and I loved it. Tabs will be great (I will install next weekend).

I wonder if anyone could weight in on my prop question

Currently running a 13-3/4 x 17 stainless steel prop (three blased) on a 21 foot steiger craft.

Half tank of gas (30 gallons) 260 lbs of gear. Runs at 4800 RPMs and 38 mph (gps) wide open.. I have no idea what the yamaha is speced to run at WOT, and I cannot find anything online.

Engine is a 1993 Yamaha 2 stroke 150 HP. The regular version of this boat weighs about 2100 lbs. This is a comercial version, but I don't know how many lbs that should add to the boat

First time out, and it felt great to me (though tabs are going to make it perfect), but I thought I would see around 6000 rpm. Engine didn't feel like it was bogged down at all.

Anyone have any insights or suggestion?

[Eggsuckindog]

No, that needs to stay under 5500 the 4 strokes go to 6 - you need drop 2" of pitch and that will put up 400RPM. Also check the engine height - Cav Plate should be 1 to 1 1/2" ABOVE the hull bottom, otherwise your dragging to much stuff in the water.

[Erie Skipper]

yep, what egg said...