I've kinda been through the gambit on the 4-strokes. Started out with a Saito .80
(old style) which cured me from buying any more of "those".

Went into the Magnum and OS line (all .91's )....all good. Easy break-in....
good idle, super reliable, easy to tune....already at this point....Saitos....n/g.

Bought a 1.20 YS from Central on sale before the conversion.....and a couple
.91's and a .63....on the last run of the .91's. I had a .91 OS in a WM Dago Red
Mustang (old Style OS ) and it was sweet.

Changed the motor out, and put in one of the YS .91 FZ's....(OMG)....set
the engine at the Fact. specs....,.1 and 1/2 turns on both needles. Fuel dots,
and tank proper.

I haven't touched the YS all season. It runs better every lap. I think now I need
to give 1/4 turn out on the low end.....the idles getting too rich. Other than that,
it's easier to run than even the Magnum.

FBD.