Recent content by sparky

Is it backfire or afterfire? Afterfire is from the exhaust whereas backfire is through the airbox. Sounds to me like an iginition afterfire. There may be a crack in one of your plug boots or in your ignition wires. The water seapage can create a short between the wire and engine head causing...

Your mechanic should have checked your valve clearance right away. It only takes a minute. Go to a new mechanic. Before a mechanic does any tear downn of the top end they need to do a leak down test first (Pressurizing the cylinder at TDC on the compression stroke). A leak down test will...

Hi Everyone, I have a 1982 XS400SJ Special Heritage. I have been restoring the bike and I was almost finished rebuilding the engine and then I got stuck. Yamaha no longer supplies the intake valves. I would really like to get brand new aftermarket valves but I do not know where to get...