Results when using a shorter drive?????
 

Would using a shorter drive cure a porpoise problem on a 208 Islander?? I repowered to a modified 502/540hp ,the power is GREAt but the boat porpoises like mad at speed. Any input to cure this problem would surely be appreciated.

that sounds like a lot of hp in that hull.also a lot of weight.what are you running for a prop?

You might try a good set o k-planes

sterndrivespec
The boat iweghs 3500 lbs and had a 454 in it so the weight wasn't changed much. Currently running 26" Bravo 1 @ 5400 spedo shows 80 no GPS so it's probably around 77 with 8% or so. I tried a Hydromotive and it was worse(way too much stern lift) I haven't had a chance to try a 27 Mirage Plus yet but was told it might not lift the back up as much. It sure would be nice not to have to put tabs on the boat. Anyone with a 1994 208 Baja Islander out there?? I need to know the distance from the bottom of the boat to the propshaft centreline. This one is 8" and I think it's too low. If I put a shorter housing on it how would it affect handling/performance. Sorry for being so long winded . /Ant info greatly appreciated

might have some hook in the bottom.....check the last few fet of the boat with a straight edge..

There is a complete set of brand new 280S K-Planes on Ebay including the pumps, etc. When I posted this, the bid was $410 (a steal). They should take care of your porpoising.

K-Planes on Ebay

The 2" short housing works great on my Baja 210 Sport. I don't know how much speed I gained because I did a motor at the same time, but the handling improved dramatically. I had excessive bow lift and at speeds above 70 MPH it would start chine walking. Now chine walking is a thing of the past even at 90 + MPH. I would also recommend full hydraulic steering for added control at speeds over 70 MPH. Especially on hulls like ours that were only designed to run mid 60's to low 70's max.

The tabs would help the porpoise, then again so would reducing the power. Obviously neither is the desired solution. I'd suggest you take a look at the boats balance. Where are the tanks, batteries, people located?

it sounds like the shorter drive might be worth a try.the boat might have a hook in it to help it plane with all that weight in the back.if you take to much of the hook out it will bounce at cruise speeds.then you will need tabs anyway.i agree with wet vette,you do need steering on that boat.if you want to try the short drive thing i can help you out

Woohoo!! Thanks for the tip! I was the highest bidder for the tabs and pumps - $1525 - what a deal :)