Set of 16 Oversize Manganese Bronze Valve Guides for your air cooled DOHC:
Honda CB750F
Honda CB900F Boldor
Honda CB1100F
Honda CB1100R air cooled engines.
 
TThese valve guides have oversize outside diameter (+0,1mm than stock).
Oversize valve guides are necessary for cylinder heads with worn valve guide bosses. Removing and installing valve guides sometimes results in loose fitting valve guide bosses and the only solution is oversize valve guides.
 
Other advantages of ABUSO Manganese Bronze Guides are:
Reduced Valve Wear - Bronze Alloy is very kind to all types of valves - Steel, Stainless Steel (like ABUSO) and even Titanium - preventing scuffing and galling of the valve stem
Heat Transfer – Bronze Alloy is has much better heat conductivity than cast iron, excelling at removing heat from the valve – one key function of the valve guide
More Valve Lift – ABUSO Guides are designed to increase the Retainer to Valve Seal Clearance. This allows fitting of high performance camshafts that have higher valve lift than stock, without damage to the oil seal.
Flow Increase – All guides protrude into the intake and exhaust port and represent an impediment to flow. ABUSO Bronze Guides are designed with optimized profile to reduce this issue and increase flow by a small margin

To ensure adequate Valve-to-Guide clearance, we recommend ABUSO HSS Reamers and ABUSO Flex Hones to finish the valve inside guide diameter after installation in the cylinderhead. This operation can be done with an electric hand drill.