Without getting into all of the details (which might make one heck of a

Without getting into all of the details (which might make one heck of a
story), I was told today (by the owner of a hobby store) that the only
difference between 2 stroke fuel and 4 stroke fuel is the label on the
bottle (including the price tag). With just under a year of experience in
the hobby I would like to know if this is fact or fiction.

If fact......it sure would make the fuel situation easier.

If fiction........well lets just say that I am not willing to ruin a new
pair of 52 4 strokes that I am planning on putting on a P-38 lightning!

All information is more than welcome........thanks.

I don't know how true that is but in the case of Powermaster fuel they
generally don't make the designation between 2 and 4 stroke and the fuel is
said to be suitable for either type of engine. They do market some specific
types for heli, car, break-in, Super Tigre etc. but their sport range is
between 5 and 25% nitro with around 18% oil (synthetic/castor blend).
Several years ago it was 'normal' (at least where I'm from) to run different
fuel in 2 and 4 strokes but this thinking seems to have changed and 4
strokes seem to be run now on higher percentages of oil than I used to use,
and the 2 strokes a little less.

Hope this helps,

If you use standard FAI fuel (80% methanol, 20% oil) you can use that in
both two-strokes as four strokes. Four strokes like to have 5% nitro for
better idle though, but still you can run one fuel in all types. Four
strokes are more sensitive to carbon deposits on the valves, so do not mix
in too much Castor oil. I use an oil mix of 30% to 50%Castor and 70% to 50%
synthetic Titan oil for both types of engine. I mix that oil in a ratio of
20% with methanol (1 oil, 4 methanol), and add nitro as required when I go
fly. I also add a bit of acetone to stabilise the fuel and help starting in
the cold. (1% max.)
Good luck, Pé

I realize that you do not live in the USA, Pe, and things may be different
where you are, but what kind of acetone are you using? Is it the solvent
that is sold at hardware stores? Or is it a different grade? Are there
different grades?

Four stroke fuel has less oil in it .four strokes only fire every 4th stroke
so cylinder temp cools between strokes the need for oil is reduced ,also
rpms are usually less then that of a 2 stroke, too much oil reduces idle
stability in a 4 stroke [thats why hotter plug in 4 stroke,plug cools down
on off stroke too much oil cools plug even more]
2 stroke fuel has more oil because higher rev & and fires every 2nd stroke
, 2 stroke oil can be used in 4 strokes, but using 4 stroke oil in a 2
stroke is risky due to low oil content[ fine tuning is more critical due to
low oil content]