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DOHC Ignition CB900/1100F
Posted: Fri Jul 28, 2017 5:10 pm
by EMS
I am working on a friend's CB1100F and I am trying to set the ignition timing. I do not understand the directions in the original service manual. It talks about a "F 1-4" timing mark which I cannot identify.
The marks I see on the pulser/advance plate are: T, I, II and S. Which one do I align with the mark for a static setting?
Re: DOHC Ignition CB900/1100F
Posted: Fri Jul 28, 2017 8:46 pm
by steve murdoch icoa #5322
Re: DOHC Ignition CB900/1100F
Posted: Sat Jul 29, 2017 12:10 pm
by EMS
Steve, don't think I ever was and probably will not be.
Re: DOHC Ignition CB900/1100F
Posted: Sun Jul 30, 2017 10:01 am
by SteveG
Mike,
The 1-4 and 2-3 marks are hard to see. The are stamped below the "T" marks. You can just see the tops of the 4 and the 3 in the picture. The 4 is red, the yellow 3.
Steve
Re: DOHC Ignition CB900/1100F
Posted: Sun Jul 30, 2017 5:16 pm
by EMS
Thanks, SteveG. This will tell me which side to use when the pulser is on 1,4 or 2,3.
It still does not anser my question which timing mark - S, II or I - do I lign up for static adjustment. These marks are "before" ( in direction of rotation) the T mark
I am assuming, it is the "I" mark, which is closest to the T mark. The others are further ahead of the T mark, i.e.: more advanced, thus to be used at higher rpm.
Re: DOHC Ignition CB900/1100F
Posted: Sat Aug 05, 2017 1:32 pm
by SteveG
Mike,
Was reading up at cb1100f.net and stole this pic:
Also learned the "F" mark = Fire, and the "T" mark is for TDC.
Steve
Re: DOHC Ignition CB900/1100F
Posted: Sat Aug 05, 2017 2:09 pm
by EMS
Thank you, Steve!
Following that explanation, would the "S" mark be the "1.4 S-F" mark then?
Here is my confusion:
The manual says to set the static ignition timing at the 1.4 S-F mark. This mark is the furthest advanced from the "T" (= top dead center) mark.
When running, the advancer works against the springs and advances the ignition even more...??? or doesn't it??
Re: DOHC Ignition CB900/1100F
Posted: Sat Aug 05, 2017 4:34 pm
by SteveG
I have never really worried about the exact spot of where the index mark "tip" aligns regarding the advancer. The manual says that "The timing is correct if the narrow projection of "1-4" pulse generator aligns with the rotor tooth."
I do that, and if there is pinging, I slightly retard. If it runs good, leave it.
Steve