I’ve been working on a project bike for a little while now and I’m having timing issues that I can’t seem to sort out.

1990 Honda CBR 600F (F1)
Crank no start issue. Question about timing the cams. There’s conflicting information between the shop manual and Clymer manual. I followed the shop manual for timing my cams (pictured) but bike will not run and timing marks on the crank doesn’t line up with spark using a timing light.

With the “Clymer” way, the cams don’t sit low enough to have the timing marks sit level with the upper surface of the head like in the picture. I originally set them using this even though the marks weren’t flush with the upper surface. Bike wouldn’t start, but I’ve replaced and adjusted parts since then.

I guess, does anyone know the correct cam position for timing on the 1990? There were changes in 1990 to ignition so I’m not sure if it is different than the other years because of the changes to the pulse generator and rotor.







New Spark plugs, correct gap
Compression is ok
New fuel pump and fuel pump relay
New vacuum lines
New fuel lines
Fresh carb rebuild
New manifold boots
Valve gaps adjusted to spec
Battery has good voltage
Coils - ohms within tolerance
Pulse generator - ohms within tolerance
Wiring correct from CDI to coils
Wiring correct from coils to cylinders