PROX Steel Exhaust Valve - RAPTOR/GRIZZLY for YAMAHA YFM 660 GRIZZLY 4WD, YFM 660 GRIZZLY CAMO 4WD, YFM 660 RAPTOR 2WD 2001-2008

PROX offers this exhaust valve for YAMAHA YFM 660 GRIZZLY 4WD, YFM 660 GRIZZLY CAMO 4WD, YFM 660 RAPTOR 2WD, YXR 660 RHINO 4WD 2001-2008. A four-stroke engine breathes through its valves. The exhaust valves open to let the burnt gases out to the pipe, then close again.

Titanium, steel or stainless valve?

This valve is steel.

• Titanium: about 40 % lighter than steel, it lets the engine rev high without valve float; standard on most modern 4-stroke motocross bikes. On the downside, it costs more and its coating wears faster if seats and guides are tired.
• Steel or stainless: heavier but very wear-resistant and cheaper; as a titanium replacement it lasts longer, with springs suited to its weight.
• Tip: replace valves as a set, have the seats checked and fit new valve stem seals.

Why choose PROX?

ProX valves come from Japanese OEM factories; the titanium versions are forged in one piece and chromium-nitride (CrN) coated against wear.

When should you replace the valves on your YAMAHA YFM 660 GRIZZLY 4WD?

Hard hot starting, valve clearance that keeps closing up or a noisy timing chain: the valve train is wearing.

Specifications and fitting tips

• Manufacturer part number: 28.2661-1

Cross-Mania tip: Check the guides and seats before reassembly and lap the valves in. Titanium valves must not be fitted on worn seats.

Also needed with this part

• Top-end gasket kit : see the selection
• 2-stroke oil : LIQUI MOLY 1 L 3065 · LIQUI MOLY 1 L 3063

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
YAMAHA YFM 660 GRIZZLY 4WD 2008
YAMAHA YFM 660 GRIZZLY 4WD 2007
YAMAHA YFM 660 GRIZZLY 4WD 2006
YAMAHA YFM 660 GRIZZLY 4WD 2005
YAMAHA YFM 660 GRIZZLY 4WD 2004
YAMAHA YFM 660 GRIZZLY 4WD 2003
YAMAHA YFM 660 GRIZZLY 4WD 2002
YAMAHA YFM 660 GRIZZLY CAMO 4WD 2008
YAMAHA YFM 660 GRIZZLY CAMO 4WD 2007
YAMAHA YFM 660 GRIZZLY CAMO 4WD 2006
YAMAHA YFM 660 GRIZZLY CAMO 4WD 2005
YAMAHA YFM 660 RAPTOR 2WD 2005
YAMAHA YFM 660 RAPTOR 2WD 2004
YAMAHA YFM 660 RAPTOR 2WD 2003
YAMAHA YFM 660 RAPTOR 2WD 2002
YAMAHA YFM 660 RAPTOR 2WD 2001
YAMAHA YXR 660 RHINO 4WD 2007
YAMAHA YXR 660 RHINO 4WD 2006
YAMAHA YXR 660 RHINO 4WD 2005
YAMAHA YXR 660 RHINO 4WD 2004