June 15, 2011

Early YPVS controller for Rd350

Just converted one of the YPVS controllers that Yamaha has fitted on the early RZ/ RD 350 bikes.
Contrary to newer models, the pcb on these units is reversed, so the dip switches are placed on the back side of the controller. Fortunately, Darren (UK) has repositioned the controller and so, there will be no clearance issues while fitting the unit.
For the stock setting, the switches 1-2-3-7-11 should be switched "on". This setting starts moving the exhaust valves at 5.550rpm and the cycle stops at 9.450rpm.
Newer Rd350 models have a setting of 2-3-5-11. This setting seems smoother, opening the valves at 6.000rpm and they are not fully closed until 10.200rpm.

It sounds like my favorite setting for the Tzr250 1KT will suit the early Rd350 bikes as well.
The suggested setting is 1-2-3-6-7-10-12. This setting while used on the early RD models will pump up some more midrange and still retain an aggressive and quick opening at 9.000rpm... just to retain the old school two stroke spirit.

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