Hello all, new member to the page here. I have recently acquired a 1975 CB360. When checking the ignition timing, the marks on the rotor seem to be off. When at TDC on the compression stroke of the left cylinder, the T mark is lined up. And vice versa, when the right cylinder is at TDC (verified by watching the intake valve open and the piston rise to TDC) the LT mark is lined up. I'm thinking someone put the cam in 180 degrees out, but I'm not sure. The bike will idle, but it is rough and almost sounds like it is after-firing thru the exhaust. I really appreciate any help, I've been searching this and other forums for weeks now, trying to find any clues as to why this is happening.
CB360 timing issue
- Thread starter 68Steve
- Start date
You may wish to double-check your findings using a positive stop of some sort.
It's not possible to put the cam in 180° out because the cam turns at half the speed of the crank. Every other rotation the cam will be 180° "out" and then come back "in" on the next rotation.
That said, the spark advancer on the end of the cam can definitely be installed 180° out, but that won't change how you're seeing the marks line up on the stator and rotor. It is possible that the stator may be installed in the wrong rotation, so that's something to check as well. The timing mark on the stator should be at around the 10 or 11 o'clock angle.
It's not possible to put the cam in 180° out because the cam turns at half the speed of the crank. Every other rotation the cam will be 180° "out" and then come back "in" on the next rotation.
That said, the spark advancer on the end of the cam can definitely be installed 180° out, but that won't change how you're seeing the marks line up on the stator and rotor. It is possible that the stator may be installed in the wrong rotation, so that's something to check as well. The timing mark on the stator should be at around the 10 or 11 o'clock angle.
