Dt 140 1994 rpms will not come up until on plane

[jweber]

I just acquired this motor on a haul I purchased..and when on the hole shot its really slow..the rpm stay down (2800ish) at full throttle until the boat works its way to plane and then it comes up to around 5500ish. Does anyone have an answer to this?

I was thinking maybe prop pitch 13x21 is prop size.

[Swanie1975]

I had a 1996 dt140 on my Haines 5.5 mwhich weighed approx 1300 kds in the water and I was spinning a 17 pitch four blade. Holeshot was. Awesome with top speed about 65kmh.

What size is your boat and are you sure of revs and speed at wot?

Cheers ryan

[jweber]

Boat is an open 18' bayliner, i may be off on the revs a bit. Never the less, when taking off wot (wide open throttle) the boat does roughfully starts out with half the rpms that the motor should do as it works it's way to plane it's speed and rpms come up and and roughfully double...at this time the boat is screaming fast..does anyone have a answer to this issue???