Build it for me. Manual powervalve cable lever

[BLOODRAGE]

Just doing some monkeying around with my Powervalved TRex and with em closed its really good for trail riding and seems to be easy on gas but when I want the power at top speed the engine gradually increases rpm.so I set em up so they were open all the time.at slow speed there wasn't much torque, but when the powerband kicked in it freaked the crap out of me. I'm into trail riding and like to open her up at times so I figured I'd see if it was possible to get somthing made up so I'm in controll of the way the valve open/closes.any ideas?

[Coupelx]

You have to spend the time to tune the valves to match the engine. it will result in a nice smooth powerband.

[BLOODRAGE]

Smooth sometimes is too slow

[Coupelx]

They work on exhaust pressure so they will react to the load on the engine. if you are wfo they will react faster than if you are cruising easy. My 392 cheetah has power everywhere it seems like. if you are looking for the typical banshee powerband hit, you arent gonna find it with a powervalved engine without defeating the purpose of the valves.

[BLOODRAGE]

I think my T-Rex is just tired,needs a re ring

[lms1977]

I think you will be defeating the purpose of the pv imo

 

 

this is me in 3rd gear rolling into the hill very slow keep in mind I am also 320lbs it is smooth

[trickedcarbine]

Stephan from the TwoStrokeShop (now defunct) might still have some of those servo kits that they used to control the PV's on cheetah cylinders. They worked in conjunction with a Zeeltronic RZ350 ignition. You could program the PV curve how ever you wanted it. Maybe you could get a set up similar to Work on the r rex

[BLOODRAGE]

The t-Rex died the other day.cylinder skirt broke.glad it happen in my yard and not wfo.

I'm not sure if the powervalves will clear my frame with the cheetah.

[camatv]

they clear stock frames but its really tight.  

 

the t-rex uses rotax valves that have this amazing screw in the top that can vary how much pressure it takes to open and close them.  trial and error can go a long way with one of those.  if the motor was getting tired and loosing comp it would affect how the valves react and open. also ruining the wrong 2 stroke oil can cause them to gum up and not open smoothly.  a proper pv motor will come off idle and into the powerband very softly and then should have the ability to rev very high still making power.  they can also add tq and hp outside of the pipes working range and extend the powerband both ways.  a pipe that feeds off of this can make a pv motor very stout.  a pipe that has way to much top end on a fixed port can work bad ass on a pv motor due to the pv being able to make the motor have tq on its own instead of relying on the pipe to do it for it.   proper porting can also go a long way as well  

 

a rider manual controlled valve would be kinda funky.  and also you would have to open and close them quite a bit..   the electronic style setup is bad ass because it works off of load more than exhaust pressure.  if the motor is loaded to much but has a high exhaust pressure electric valves would stay shut to give the motor the tq it would need to pull out of that kind of situation.  i believe a lot of snowmobile's are using this for pv control now.