Classic Motorcycle Mechanics

Seal the deal…

In my life I have always considered two-strokes to be trouble and in my experience the more pots, the more trouble; ergo triple trouble delivered by the purple pestilence!

The last job to do in the engine build frame was to refit the check valves at the bottom of the crank cases. These were an idea Kawasaki Heavy Industries dreamed up in 1974 for the H2B onwards in an effort to do something useful with any oil building up in the bottom of the crankcase when the bike has been idling or slow running, and to attempt to reduce the noxious smoke cloud from the exhausts when one is back on the power. When the engine revs up again crankcase pressure increases, forcing the oil into drillings at the bottom, which then feeds oil into the one-way check valve and then into the left-hand main bearing of each

You’re reading a preview, subscribe to read more.

More from Classic Motorcycle Mechanics

Classic Motorcycle Mechanics6 min read
Power Broker!
Last month I left off having had a pretty successful return to racing but with plenty of room for improvement. Suspension wasn’t where it needed to be and neither was ground clearance, both relatively easy to fix, and I had a few weeks to go at it be
Classic Motorcycle Mechanics1 min read
New CRMC website!
The Classic Racing Motorcycle Club has a new website up and running. Mark George from the CRMC says: “We hope people will find everything they need to know about racing and parading with the CRMC on the brand-new website, which has a new, fresh look,
Classic Motorcycle Mechanics6 min read
Bolt From The Blue
Last time out, I’d just bought a stunning looking, Sonauto-liveried 1990 Yamaha XTZ750 from eBay, at about half the expected price – £1500. Why so cheap? Well, the bike had a coolant leak which the seller had diagnosed as a head gasket problem and al

Related Books & Audiobooks