Hi Tom/Samo,
I may just be a bit paranoid!
Was thinking about my governor hiccups and the best way to allow for mech wear on linkages/fine tuning.... I ran around in circles rebushing all the hinge points and removing slop to the point that the governor eventually started to bind if the lube dried out... In the end, all I found that was needed was a SMALL spring pulling on the pump rack to pretension the linkages(in line with the IP rack)... probably way less than 1oz load...This neatened up the seesaw and got things nicely stable... I also found, that with this spring in place, governor mech adjustments became quite precise....in real terms, it amounts to around 1/2 to 1 1/2 turns on a 6mmx1 nut to adjust the frequency +- 5%... Ideally, have the pretension spring on the closing side of the pump, so if a linkage loses a pin, the rack pulls closed and the beast shuts down.... On my unit, it is the other way round, it is pretensioning open rather than closed, not an ideal situation. The reason for this is that my rack doesnt have a place to hook the spring into.... When I rebuild the pump, I will employ a drill and sort that small matter out...
Given the small amount of spring tensioner travel required to fine tune the frequency when slop is catered for(+-1 to 2 mm on my setup), you might be able to end-pull the spring quite well if you reduce your pull radius. I, personally, am not wild about R/C servos and the like....I have put too many heli's into the ground when they have failed on me due to vibration, hence the suggestions....(Incidentally, when the servos have failed, they tended to fail in such a manner that they locked fully one way or the other, might be worthwhile to see your overspeed rpm(safety please!!), with the servo held fully in max throttle position with no load on the engine...
Just a thought....
Cheers
Paranoid Ed