what year power valve parts fit 1985 yz250? also the round power valve cover ?
The opening of the exhaust is where the term "on the pipe" comes from. What RPM the power hits depends on your exhaust valve and expansion chamber configuration. Regardless of the type of the two-stroke dirt bike engine, the power valve will close at low RPMs and open at high RPMs. The way it achieves this is via the valve's governor.
We do not have any power valves, but I would suggest you buy an OEM power valve for the '99 YZ250 as it was a better valve. Thanks, Scott Weisz Technical Sales Forward Motion at Millennium Technologies 1404 Pilgrim Road
Yamaha YZ 250 YZ 125 Power Exhaust Valve Governor 5X4-11921-02-00 99-01. $6.95. Trending at $12.99 Wiseco Titanium Intake Valve for Yamaha WR / YZ 250 / Gas-Gas EC 250 VIT005. $119.95. 3 left. Intake Exhaust Valves Kit For Yamaha YZ250 YZ250F YZF250 WR250 WR250F 2001-2013.
1984 yz250 power valve i need a new power valve and am having trouble finding one is the 1984 year compatible with - Yamaha YZ 250 question Search Fixya Press enter to search.
There is one on the valve end, and the other is on the linkage plate that attaches to the valve. It will run in either position, but if the marks are off, the valve is 180 degrees out of phase. The valve is then operating exactly opposite of the way it is designed to. Top end power will be non existent.