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"trainfan1" wrote in message
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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

The high speed carb. adj. was set to best h.p. with all oil ratios. The very
rich oil mixtures always made more h.p. Your explanation is correct that
adding oil will cause the leaning out situation, but not in this case.
Dixon