Yamaha F70 on a 20 MA?

[FishStretcher]

Fr. Frank- For some reason, I thought you rigged a 75 HP once, but I couldn't find a reference.


I noticed one of the recommended power options on the Mosely site was 80 HP for a 20CC and stated 35MPH top speed. But a 1400lb hull weight.


I don't run a heavy boat and was estimating the mass benefit of a foam transom and a 110 lb lighter outboard. I wish the 90 was a bit lighter, but it's not.

Originally Posted by Fr. Frank

I actually did rig 1 (one) 20' with an Evinrude 70 back in the early 80's. It could get the boat on plane but was clearly inadequate. But customer is always right, eh?

I think 85-115 hp is the right HP range for the 20' if you're worried about weight. Your F100 is a good motor . If you're getting airborne in the heavy chop trying running with the motor trimmed all the way down. Adjust your propeller torque tab for that configuration. Alternatively, and better yet, let me suggest adjustable trim tabs. Keep the nose down and it's much harder to get airborne.

The 20' was designed for a single 275-315 lb outboard, or in the case of some of the wide transom cut-out models of '68-73, up to twin 50-65 hp motors at 190 lbs each.

The very first Seafari I rigged back in '83 was a '69 re-rigged from its original twin 190 lb '69 Johnson 55 hp 3-cylinders to a single Mercury 140 ELPT inline 6 weighing in a bit over 300 lbs