I inherited a '79 Yamaha XS400 (2 cylinder, 4 stroke, air cooled, SOHC, duel carburetors).
The timing chain had broken so I replaced it, setting the timing at the same time.
I cannot start it. The spark plugs are sparking and they get wet from fuel, but the engine does not fire. We managed to get a couple of little puffs but nothing else.
We removed the air filters and sprayed engine starter into the carburettors and this resulted in small flames shooting back out of the air intakes.
We also tried advancing and retarding the ignition timing.
Would anyone know what I could do? Could I have set the timing wrong?