Guitarguy1996
XS400 Member
Hey guys! So I've got a 1980 XS400 that I got as a complete project. It needed a new timing chain, piston rings, rocker arm, and head cover. I tore it all the way down and completely rebuilt the motor and it's looking great. Also, the wiring harness was beyond messed up. The previous owner just cut everything not 110% necessary for it to start which left me with reconstructing everything he cut. It's far from done but I've got it to a point where I should be able to start it and hear it run. I tried to fire it up and after a ton of cranking....um.....the dang thing caught fire! Shot a big ol flame out the carb (wasn't running a filter at the time so I could give it some carb clean to help it out) and lit some spilled gas and the masking tape tags I had made for some loose wires . After breaking my fire extinguisher virginity, I realized I put the cam gear in upside-down. Pulled the head cover, flipped that around, re-set the cam timing, and the same thing happened! Big ol flame out the carbs! Both cylinders have 125 psi of compression so I don't think I'm off enough for it to be a valve timing issue if I'm off at all. All valves are adjusted to spec (.10mm intake, .20 exhaust if I remember right) would this be ignition timing? It's got a CDI ignition on it instead of points so finding info on how exactly to time it hasn't been too easy. I'm sure the process itself can't be hard but I wanted to throw it out there before I tore into it again today and set the whole d*** garage on fire thanks guys!