I have a student I am teaching that has an Alpha 9 trainer with an Evolution engine. This engine has been a really bad one! We finally have the carb acting somewhat correctly, but I need to go a little leaner on the low end mixture. There is a retainer plate to keep you from moving further. I need to rotate that plate... is this possible, and how?
Bill R.

Sounds like you're talking about the blue limiter collar?

There is a set screw, similar to a wheel collar...just loosen that, and re-position the collar...or you can just remove the limiter completely. (I've done that on several Evo engines w/o any problems...as have several other people )

I just removed it on mine. It's there to keep Newbies from adjusting the carb beyond a narrow range. I think that anything you can remove from a trainer that isn't nedessary, the better it flys...KISS principle.

I had one of these engines that did thatand it drove me nuts. So I contacted support and they gave me this info from the manufacturer:

Some of these engines slip through QA with the wrong Low-End needle setting. To set it correctly,

1 Remove the blue collar.

2 Open the carb 1mm (One Millimeter)

3 With the carb open 1mm, close the Low-End needle

4 open the Low-End needle 1 1/5 (One and one fifth) turns

5 replace the blue collar