Topic: CB500 timing issues

[bdillworth]

I have a 1971 CB500 and I just did a top end rebuild.

I’ve installed pistons, rings, gaskets. Adjusted valves. Lapped valves too. Followed the manual on setting the chain tensioner and camshaft positioning to TDC. (Top dead center)

I have the dyna s ignition, however I am having troubles setting my timing correctly. With the test light on the blue wire I’m seeing that my timing is on 2-3 when it should be 1-4. I switched the wires and it instantly started up but I’m not sure if that’s a good thing or not.

Why would the timing be backwards?

[Scott S]

 Check how you have the coils plugged into the main harness.

[bdillworth]

Colors match up. Black wire with white line connected to the coils along with yellow wire. Seems to be correct to me.

[Scott S]

 Did you install the Dyna on the advance mechanism 180 degrees out?

[bdillworth]

I have taken the dyna off and rotated the engine 180 degrees and installed it again, but still the same timing issue. Might I have rotated too much?

[Scott S]

 Who put this back in the Open Forum? It's an SOHC4 question.


 Anyway, if you just pulled the entire mechanism off, rotated the engine and put it back on, that doesn't really do anything.  Didn't you have to install the magnet/pick up onto the stock advance mechanism? That's what I mean by being 180 out.

 Here's a video where he talks about it:

[bdillworth]

I actually went by this video already, the rotors magnet in the advanced mechanism may need to be turned 180 degrees. I’ll try that today after work. Thanks!

[bdillworth]

Update, everything is back to normal.

The rotor was in the wrong position on the timing marks 1-4. The magnet circle is supposed to go to the left of the 1-4 marks. Not line up with the 1-4 marks.

Thanks for you help Scott S.