Low budget OMC twin project

[sWaltsu]

Hello

this is my extremely low budget motor / boat project.

I had bought couple broken OMC motors. Old 50hp with BIG electric shifting gearcase. Second motor is 1982 60hp.

First motor (old fifty) was overheating and piston was melted. Gear case is full to water...

Second motor is better.
I will replace just piston rings, seals and gaskets.

Because motor is opened. I might lightly modify it.

change reed valves to fiber model, clean all flow path and increase cylinder compression.


cylinder holes must be modify!


exhaustpipe must be shorten

all bearings is OK. But how fast i can run it, with standard connecting rod, pistons and crankshaft?
6000RPM must be ok, but how it take over 6500RPM?
How much i dare to set ignition timing (degrees)


This just purpose to learn to get more power to propeller.

Two motor, boat and lot of building parts, was cost less than 300 USD.

any ideas what else i must do, to get more power?

Setup:

Gear case (2.4:1 ratio)


four blade "home-made" Cleaver (23")


hull without deck.

--- My other projects---

Bat 22 offshore
and
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