ORIGINAL: XJet
ORIGINAL: extra-nut
XJet
balance your props and your engines will shake LESS in flight, not more ! Hell , you might even be able to get a few more mph out of your trainers. Just my opinion...
Don't worry, my props are balanced and my low-end is leaned out perfectly (1/8th turn richer than a failure to transition).
My SA100 is in a Mojo 60 profile 3D (which is light at 5.5lbs) so the torque pulses are *really* noticeable.
Strangely enough, my SA82 is in a *really* flimsy profile but it hardly vibrates at all.
Quite a few people I've spoken to say that their 100s also really shake -- but some others don't. Likewise, some folks have 82s that are bone-crushers -- but mine's not.
I suspect that some Saitos are just more inclined to vibrate more than others -- end of story.
However, one thing's for sure, the vibration level of a very light and powerful 4-stroke will always be higher than that of a 2-stroke of the same power (assuming all else -- like prop balance, etc is equal).
I'm about to try using wooden props to see if the reduced mass will also reduce the magnitude of the reaction-torque pulses and therefore the levels of vibration. Some guys have had great success with this approach.
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Xjet, as an engineer you should know that there is not enough latitude in the production of these engines for some to be significantly more out of balance than others.
I'll bet those complaining of shaking are those trying to break-in their engines while flying. This is not meant as a shot. But I'll bet it is the truth.