In article ,
"Roger Long" wrote:
"Jere Lull" wrote
A new 2GM20 will put out about the same power, perhaps more
The new 2 cylinders are called 15 HP engines but it is the ratings that have
changed; not the engines. Our "20"QM is really a 15.
Sister boats with the old raw water 3GMs max out no faster than us and
are usually a bit slower. They always burn more fuel.
You can't go just by the numbers, as the older engines were geared
higher. Faster shaft and prop, more drag, less effective power. We swing
a 16x10" 3-blade.
--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
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