dixon wrote:




This isn't exactly answering your question but, I have done a lot of
dynomometer work on two stroke outboards. Contrary to popular thought 50 and
100 to one oil mix is detrimental to horsepower gain. In every test I've run
we get the most h.p. with very rich oil mix. On a recent test, a 50 h.p.
Merc. made an actual 39 h.p. with 16 to 1 mix. When the ratio was changed to
8 to 1 (yes 8 to 1 ) it made just over 40 h.p. Even at 8 to 1 there was no
noticable smoke at high speeds. Idle was a diff. story. The extra oil seals
piston skirts,reeds and between cyl. crank seals. If motor life and max.
h.p. is your bottom line run as rich oil mix as poss. to a point where plug
fouling becomes a problem. I have a PWC 951cc. that runs 6600 rpm with
factory set oil injection. With the addition of 32 to 1 premix along with
oil inj. the rpm is high 6700 to 6800.
Dixon



Easily explained - as you know, a richer oil mix leans out the fuel
mixture(effectively making the jet size smaller) - which 2 strokes are
very sensitive to - resulting in your higher power outputs at the risk
of burning a hole in the piston, and setting up a "carbon fire" in the
cylinders that will be hard to put out...

Rob