[Bushwacker]

The 20' hull was designed in the mid/late 60's when the biggest OB motors were about 300 lbs. The 7' beam is relatively narrow compared to new boats, which is one reason it rides so much better. If you make it stern heavy with a 500+ lb motor, it won't ride as well and you'll have trouble getting it to plane at 12-13 mph for a comfortable ride in rough seas, and self bailing at rest will be a problem. Been there, done that.

Will it work with 500+ lbs of motor? Sure, and a lot of guys on this forum run 400-500+ lb motors . . . it's hard to find a 300 lb motor these days! And the Seafari is a little less stern heavy than other models, so it's more tolerant of a heavy motor. Also Potter raised the cockpit sole in about '74, so the later models will self-bail a little better. My point is that a lot of folks have never operated these boats with a light motor and IMHO, don't appreciate how well they ride and handle when they're balanced per the original design specs.

I ran a 300 lb 115 V-4 for over 30 years before I repowered with a 429 lb motor sitting 30" further back. Although the big flotation tank on the Hermco bracket kept waterline within about 1" of previous configuration, initial low speed planing performance was terrible . . . wouldn't plane below about 18-20 mph. By changing to a stern-lifting 4-blade prop, and adding a Doelfin I finally got back to where I was with the old motor!

Would I do anything different if I had it to over again? No, except maybe go with a little shorter bracket, but I do like that big swim platform for diving, and I think the solid transom is a big safety factor. But the only 4 stroke I considered was the 140 Zuke since it's about the same wt as the E-Tec. However I wanted the extra omph of the larger displacement, and I seem to be running with heavier loads than ever, so the extra power is nice to have for those conditions.

Although Honda makes great motor's, I'd prefer a 140 Zuke
because of it's lighter weight, chain driven cams, and the offset driveshaft/greater gear reduction. If you don't care about weight, the 175 Zuke is about the same weight as the 130 Honda, although I have no idea what a used Zuke goes for these days.