Exhaust Valve 40mm

Compare to 11341257837 BMW valve. 

Sold each, one per cylinder head, two per bike. 

In our lengthy experience overhauling BMW heads, these European made top quality original equipment style two piece unleaded exhaust valves are superior to the aftermarket one piece stainless valves for durability and long life. The stem is through-hardened at the tip to prevent wear in the keeper slots and to provide an ideal surface where the rocker strikes the valve, then it is hard-chromed to prevent galling in the guide which extends guide life while allowing close tolerances. The lower part of the valve has the latest unleaded compatible alloy to withstand a long hard life in the combustion chamber and the sealing face is Stellite plated for extreme durability. 

Although these valves will work with stock valve seats, our unleaded valve seats are recommended to prevent seat recession common in the stock valve seats used up through 1985. Fits all R90 and R100 models. Upsizing to 40mm exhaust valves is recommended when installing R100 cylinders on R75 and R80 models (which use smaller 38mm exhaust valves) if having head work done at the same time.