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YPVS Valve Opening Speed of Rotation....

Posted: Mon May 22, 2017 1:50 pm
by WVWRZ500N
Hello Fellow Club Members and Future Members:

I've got a question that I'm beginning to mull over. I've been running The Beast around and have some question as to if the power valve is actually opening fully by the time the bike is accelerated past 2nd and even into 3rd gear. By the time 4th is geared I can certainly tell that the full power is coming on as the acceleration experienced is near twice that of the previous 3 gears. I'm ordering a camera to try and get some videos of this but that'll be a few weeks.

Has anyone else experienced anything like this? Is there any way to increase the rate of speed to which the power valve actually snaps open? I'll admit the electronics side of these machines is not my specialty and more like a weakness unless the typical problems.

Cross posting this for more help if you see it elsewhere on the board.

Thanks in advance for the input.

Re: YPVS Valve Opening Speed of Rotation....

Posted: Mon May 22, 2017 2:09 pm
by silverstrom
The valve will not "snap" open. To do so would be pointless unless you're chasing that light switch narrow powerband of non-YPVS bikes. The RZ500 has a fairly narrow operating range. The valves start to open at 6150 and are fully open at 7950. Compare that to the TZR 2MA/1KT which is 5850-10050 or the late model RZ350 at 6000-10200.

The powervalve servo gets its operating signal from the powervalve controller. If you want to change the opening range of the powervalves you need to alter the signal coming from the controller. To do that you can send the controller to Nick at Two Stroke Race Labs, or buy one from Zeeltronic. Both will let you select the begin to open point and the full open point. If you are looking for an extremely narrow window you can set both points very close together. I prefer the Two Stroke Race Lab option and the ability to simply move the 12 dip switches to get the RPM points needed.

Re: YPVS Valve Opening Speed of Rotation....

Posted: Wed May 24, 2017 8:47 am
by phildu31
As John said the valve opening is directed by the controller based on RPMs.
You define the RPMs at which the valves start to open and the RPMs at which the valves will be fully opened.
Between these 2 values, the opening curve is linear vs RPMs.
All Yamaha controllers had the same components, the only differences were in these 2 values that were set accordingly to the bike.

If your controller is out of order, the best option is to send it to Nick who will repair it ( if possible ) and add the 12 dip switches.
4 switches control the opening start value, 4 others the opening end value.
The last 4 switches control the opening aperture range : so you can even close more or less the valves at low RPMs as you want.
But keep in mind that this will also affect the oil pump.