I'd say it's probably a rotary valve Reg, here's some pics from Vario's site. Can't tell you anything more than that.
http://www.vario-earthmovers.com/bau...0-teil-10.html
I ran the HK last nite for an hour Greg, the 1st time in a couple of months, and it really sucks in fluent movement compared to the 850.
I tried when I 1st got it last July to make the ch mix work via radio menu & couldn't get nothing. Last nite I was gonna try to adjust some of the valves EPA's similar to how I programmed the 850, and couldn't get into the menu settings. And playtime for the HK hoe ended when the lights flickered & then the pump rpm slowed right down... I tried it today & the pump speed is still slow, like the esc might be junk?! Crap crap crap!
When I get my DX8 rx replacement from Albert, I'll try that Spektrum radio to improve the model's performanace... if it's possible?
Also, when I parked the HK last nite, I noticed alot of oil sitting atop the boom cyls, could the seals be toast already?!
Idk? this is a pretty crappy model compared to the german ones... or atleast mine is. I like this model’s range of motion & reach, but the radio & hyd system is garbage! I might have to change it all before I get it working as smoothly as the 850.
Here's a video with the HK 1st, then the Stahl.
http://www.youtube.com/watch?v=KovkRSYJSGQ
After using the 850 virtually everyday for the last month, these two smaller hoes are kinda slow & unresponsive in comparison.