quoting cmoulder:

"Zero down is correct for this model, but zero right? All models need some right."


Agreed, cmoulder, despite all of the long winded debates at the airfield (which I have learned to avoid, too smelly) a tad of right thrust usually counters the PEE factor or whatever as the propwash comes around helically and kicks the fin, yada yada yada..... I generally just stay on the rudder the whole time whether hovering, KE, landing and prefer the motor and fin straight- right thrust and fin only cocked in the right direction by my "tolerance" or measurement error which I think (pray) is about 0.5°.
To be honest, the one thing that I really "ARFED" is bolting on the motor to the stock mount. I twisted it between the rails to get rid of downthrust and figured that I could washer the side thrust later. I cannot go by the incidence meter numbers or my eyes on the right thrust. My eyes work for right thrust if I get up in a chair& look down....but that all goes away if I mount the engine at 45°/RHS per kit instructions- just can't see it. (BTW that 45°will mean no cutting the cowl for the Saito 91's valve covers!) (EDIT:Iwas wrong... had to cut the cowl for the valve covers.)It seems a little dicey (in my limited experience) to use my incidence meter's prop drive washer mount with the plane sideways to measure right thrust- no good 0° reference. But measuring the same blade on LH and RH sides to the center of my (straightened) fin reads zero. I've only flown in high wind so far, so the rudder comps are full time anyway. Yes, right thrust would be good, but at the 1 degree level, its not noticeable in puffy 15-25 knot winds. What IS noticeable is my severe pucker factor with such a light plane in those conditions for the first 5 flights!!!
Gotta love the airbrakes for landing without rolling over, bouncing or stalling in a puffy crosswind.

MAGIC?!?!: Good point about the cowl-the whole motor appears to be CL slightly to the left(3-5mm?), which does effectively give a tad of right thrust IMHO- as in standing on the rudder in a twin when one engine goes out. The center of force is left of the center of drag, so it goes right. But now you have me questioning my prop tip L/R measurement- which is only good if the motor is on centerline.
Dam- there goes my evening!