Avon RIB 340 Planning issue

tvomosswood · 27 June 2016, 15:39

I have an Avon R340 with an 1996 2strokes 8HP Johnson about 58lb it ride really nice with one adult, with two or more, it is more like a nice slow cruise. I put on a 1999 Evinrude 4 strokes 15HP about 104lb, but now with one person it really lift the bow out and I either have to sit on the floor or use an extender so that I can move my weight up toward the front more. I have adjusted the engine angle and it seems to be perfectly straight up and down. What else can I do so that I can sit comfortable on the tube and operate the boat by myself? Would whale fin on the engine help with this issue?

Nos4r2 · 27 June 2016, 17:19

15hp on a 340 should plane easily. I was using one to run up and down the Intercoastal in FL and it planed easily (granted, it was a 2 stroke Yam 15 and it had a whaletail on) with me at the helm and I'm not small. I didn't have to move forward either.

Ron Noco · 27 June 2016, 22:05

Hi,

Are all other things equal?
i.e. Same shaft length, does it sit deeper in the water?
What's the Prop diameter & pitch, science in itself as I've been learning

HDAV · 30 June 2016, 19:32

Run a 25hp on a 340 (console rigged)

And nose does lift, ballast up the bow, with the console it's easy just stand up and lean over the wheel until on the plane/plain then sit down and enjoy with extra body onboard no bother....