Boat will not plane when heavily loaded

[jackmorgan]

That's a big heavy boat. This guy has a 248 vista and says his is a 5.0 GI 270hp, I'm sure he is empty and by himself but who knows. https://www.youtube.com/watch?v=7NDrcnrqh7Q here is a 258 but not a speed test https://www.youtube.com/watch?v=El8DoMM9754 I would want a 8.1 for that big of a boat, but that's me. My 5.0 GL took about 14 secs to plane with a 18" 4 blade. I have now made it to a 6 sec plane with a 21" 4 blade, a lot of tweaking. At the same time if i weigh the boat down to 6 people I'm not a happy captain again, I just bought a 350 block for the low end grunt.

Well if this is 'normal' i guess i want the 8.1 as well. this was the largest engine at the time as far as i know. I'll see what happens when i replace the cap and rotor ... fingers crossed.

 

[Jason89sunbird]

http://forums.iboats.com/forum/engi...rives/57178-performance-chips-for-volvo-penta

an interesting bit of info from Don about the difference between GI and GXI

 

[Jason89sunbird]

This post about the fuel dampener might lead you down the right track

http://forums.iboats.com/forum/engi.../10186534-high-lp-fuel-pressure-on-vp-5-0-gxi

 

[jackmorgan]

If you are able to, check your prop set , should be F-4

checked yesterday - they're F4

 

[jeffnick]

The first thing I'd 'do is 2" inches' less pitch,, or remove the cup if you have one. I had a 16 footer that wouldn't plane with 4 people unless everyone crowded forwards,. Two inch less pitch solved the problem, but destroyed the top speed. The other answer is more horses...