Re: won't plane over
I had a 55 on a 15 foot Glastron deep vee. It went 27 mph. Sounds like your speed is a little low, but not much. You would probably expect about 22-24 on that tri-hull.
Try playing with the tilt pin adjustment. You want the propeller shaft to be fairly close to parallel with the keel. Mine was on the third hole out (of four holes) It makes a big difference on these smaller engines.
Also, props are still available for these engines. If you have a tach, these engines are supposed to run 5,000 to 5,500 RPM rated 55 horsepower at 5,500 RPM. Re-prop to get the best performance. Try iboats and if they have nothing, try franzmarine.com.
35,45, and 55 were all common blocks and legs with minor differences in bore and stroke. All used the same series propellors. 10 3/8 by 11,12,or 13 pitch three blade. Michigan made the same props used on Evinrude/Johnson; only difference was Chrysler had a different hub. So if you have an old E/J prop in good condition, just re-hub it with the Chrysler bronze, splined hub.
