I thought I would add my 2c -I have this 1.00 engine in a 1/4 scale Pitts - and had a lot of trouble trying to get it to run properly - long story short I hadnt flown it after the first flight when the motor cut out ( got down OK though ) as I couldnt trust it to keep running.
Once I removed that stupid low speed needle limiter and was able to tune the low speed needle so it ran properly - all the problems went away - so its my belief that the very limited range of adjustment allowe by this system ONLY works in some cases - where I live the needle required a different settinf to that allowed ...remove the limiter and the problem went away.