"Stan Stannard" wrote in message
...
Hi My Mariner booklet which is for 2/4/5 hp models (My engine is No
052021)


states 25:1 for breaking engine in then 50:1 after break in. I can scan
and

My new Johnson 8 hp said the same thing, although the Johnson
dealer recommended not doing that - says put 50:1 Evinrude/Johnson
X25 and go have fun, just stay out of WOT for a 2 hrs. Fear of 25:1
(or excess oil in any circumstance) is that you'll get carbon build up
on the head, plug, and tops of piston (which isn't so bad other than
possible points for pre-ignition), but the risk is carboning up the
rings to where they get stuck in the grooves, and lose compression.
I recently tore down a Sea King 7.5, and the rings were completely
frozen in the ppiston grooves to where one of them broke when
trying to carefully pry it out. I've seen this a LOT in chainsaw, and
weed-wacker repair/rebuilds, but some of that is also from
high ash petroleum based oils like Ryobi, and all that other
crap you see at Home Depot and the like. Some equipment
manufactures seem to thoerize that slower reving engives need
more oil, and sometimes based on bearing design etc., however,
*no* 2-stroke in my mind is slower reving be it a chainsaw,
blower, weed wacker, or boat motor. In my mind, the faster
the motor runs, the less oil in the mixture you need since you
are moving so much more of the mixture thru the engine, but
thats just my firm belief based on years of flying large model
airplanes with 25-45cc engines (I settled on 75:1 for them).
50:1 (with good oil) is a safe bet if you are squimish, but I'd
ask questions if any manual or manufacture is telling you to
run a lower ration (more oil). Because of ash, and carbon,
more is not always better (expecially since carbon is adbrasive)