Stumbled into this the other day. I suppose some of ya know these guys. In the first part of the vid(before they go to the woods), are fantastic factoids about the 900 series. I wish I had time to diddle around like that!
Anyway, if you haven't seen this and are interested in the 900 series;
Handle AV's on the bottom change a lot after the 910....even went to a Partner type, integral wrap handle system. When I get my 910 back together....I'll take some pics of that 910 AV system with a West Coast full wrap handle. There's a steel post that's anchored and pokes through the wrap handle so that it limits how much travel can be in the wrap handle. I'm thinkin' that a J'red engineer's kid came up with that while playing with Legos. Nobody in this vid said anything about a rev limiter in the module, just the Tilly governor that has an easy, well known defeat trick. Personally, probably because I'm used to working in the woods, I don't think these saws should be allowed to wrap anymore than 12 grand....OE parts are too rare and the aftermarket doesn't always supply pistons & jugs. Have some reservations about GOLF et al.
Most people curse those Tilly governors but I can't ever think of one failure in all the loggin' saws I had with 'em. Like everything else in a carb, they have to stay clean.
Kevin