'66 Evinrude 33hp - Am I getting top speed or need adjust?

[peterswanson]

Hi all.

I recently put a '66 Evinrude SkiTwin 33hp on my 16' Herters Yukon fiberglass boat. It's rated for up to 40hp. The boat supposedly weighs 285 lbs. Add to that 3/4" plywood casting decks, the motor, a 28 lb thrust trolling motor, 12 gallons of gas, an anchor, fishing gear, pedestal seats, and a plywood console (side console steering/controls.)

Boat can be seen at www.listedbypete.com/boat.htm
The last two photos are the boat as it's set up now.

This boat is sweet. Absolutely love the upgrade, as everything works as it should. I'm getting about 18-19mph with two adults (one 200 lbs, one 220) and about 23mph by myself. I've tried a couple of (manual) trim positions and it seems that one pin out from the furthest-in is best for the boat. The motor also has Doel-Fin hydrofoils installed on the cav plate.

The throttle control (probably same vintage as motor) doesn't have much forward throw, but I've noticed that the throttle control on the motor also has a very short throw. I thought that maybe the throttle wasn't advancing to full WOT position, but I think it is.

Anybody think i should get a bit more out of the motor, or is this all she's got? The carb was recently rebuilt, and the motor starts, runs and idles smooth. Should I try to adjust the high speed jets while my partner runs the motor at WOT to see if I get a bit more out of it? I noticed that the high and low speed adjustments on the carb are accessible with the front panel (where the pull start is) open, and that they are connected to the throttle linkage with (plastic?) rods...never seen that before.

Don't know if I should mess with it or just leave it as is and be thankful that it runs smooth.

Thanks for whatever advice you can offer.
Pete

 

[lindy46]

Re: '66 Evinrude 33hp - Am I getting top speed or need adjust?

Nice looking rig! You could try adjusting the high speed jet to optimize, but doubt you'll get too much more out of it. A higher pitched prop may add a few mph's, but I'd probably be happy with it the way it is. You can make sure it's wide open: with motor not running, put it in forward and advance to full throttle. Check the butterfly in the carb and make sure it's opening all the way and is horizontal.

 

[peterswanson]

Re: '66 Evinrude 33hp - Am I getting top speed or need adjust?

Thanks, Lindy. I'm happy with it, but just wondered if I could get a little more. I recently put a new prop on it - a Michigan Wheel replacement that's a 12 1/2 pitch. (Lost the other prop due to not checking the cotter pin in the prop nut...oops.)

I'll check the throttle linkage today to see how far that butterfly opens when it's open...I noticed that when I advance the throttle lever it bottoms out at the end of the throw as it hits the end of the control slot. Have to look at the cable to see if it can be adjusted at the end where it locks into the motor...it's such a short throw that any little adjustment might get to WOT. The entire range from idle to highest is a very short distance with the shift lever. Thanks for your input.
Pete