erm... although I agree with much of your post, I'm gonna hafta disagree with this bit;
...your mix ratio is always the same no matter what the oil bottle says. your engine manual should tell you what mix ratio you require...
This is... not always true and with the in frame Chinese two stroke kits, it defo something to be questioned - some manual/manufacturer's recommendation of
16:1 fuel/oil is a prime example. Excessive to the point of bordering on insanity, some have theorized that it's if your using
motor oil instead of a quality two stroke oil. As the design is based on a 1950's Russian motor
http://motorbicycling.com/f4/russian-engines-d-4-d-5-a-6820.html and given the potential scarcity of advanced lubricants in the region - the theory seems sound.
Additionally, should you actually do the following, you
will suffer an extremely excessive buildup of unspent oil and deposits;
if the bottle recommends a ratio of 50:1 or 100:1 and your manual says 25:1, you still mix 25:1
Run w/e ratio your comfortable with, but if you wish to run as rich an oil mix as the above, get an oil that's made for it
not one designed for 50/100:1 as those aren't the same as normal non synthetics. 32:1 with a quality non synthetic is pretty much the norm after break in.
As an example of some of the advancements made in synthetics (which obv are unaccounted for by the manufacturers), we've this rather long thread regarding the use of as "radical" a ratio as 100:1... you may wish to skim through it a bit to review any number of testimonials made by quite a few members
http://motorbicycling.com/f3/100-1-mix-9850.html
While I'm not suggesting you should run such a lean oil mix - it does quite clearly show that the "manual" doesn't accurately reflect what your engine "needs" & I will say that I'd be far,
far more likely to trust the
oil manufacturer's recommendations for their product than the... so-called "engine manual" included w/these kits lol