No ignition timing marks?

If it's broken or just needs tweaked

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deetrumpet
Posts: 7
Joined: Fri Apr 08, 2011 10:59 am
Location: Los Angeles

No ignition timing marks?

Postby deetrumpet » Tue Apr 19, 2011 2:38 am

I don't see any timing marks on my 1982 CB650. (I do see setup to change the timing.) Of course, my timing light is no good without marks. What am I missing? Should I post a photo? Help!

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Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: No ignition timing marks?

Postby Volker_P » Tue Apr 19, 2011 4:27 am

Please have a look at page 3-4 in the manual linked below to get an idea where to look for the marks.
If you still can't figure out then, in fact a picture of your pickup/advancer region would be interesting.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

deetrumpet
Posts: 7
Joined: Fri Apr 08, 2011 10:59 am
Location: Los Angeles

Re: No ignition timing marks?

Postby deetrumpet » Thu Apr 21, 2011 1:46 am

I'm not clear on what the "1.4 F-I" mark looks like. (I understand the 1.4.) As this photo of my bike shows, there is a T with one notch above it, and an F with two notches above it, and a small 'I' between the T and the F, and a small S to the right of the two notches.

Or maybe I'm misreading what I see above the F -- maybe that's not two notches, but rather one notch directly above the F and an 'I' just to the right of that notch?

In any event, I need to understand exactly which mark to line up with the stationary index mark when I use my timing light.

Also, when I check the centrifugal advance with the timing light, I don't understand what the "full advance marks" look like (i.e., how I will recognize them when I see them).

Volker, I sure appreciate all the expertise you've shared on this site! I just bought a 1981, with a lot of deferred maintenance, and I've worked on auto carburetors and ignitions but motorcycles are new to me.

Brett Klein
Los Angeles
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Honda timing marks 1.jpg
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Volker_P
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Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: No ignition timing marks?

Postby Volker_P » Thu Apr 21, 2011 2:36 am

I must admit that I did not care for that so far. I just put the engine on the left notch of the 1.4 F (and later 2.3 F) mark and align the pulse generators with the nose.

From my understanding, the T mark is TDC, the 1.4 F-I mark is the left notch above the F. That's the one for the light at idle. The right notch is the S mark that I probably should use for the visual method instead of the left one. :wink: ..... Thanks, I think I just learned something new! Seems my German manual is not precise here.

Most advanced position should be 28.5° off to the right. Turn the engine to find the mark there about another two times the angle/distance from 1.4T to 1.4F-I. Possibly there is just a notch or a double notch. I don't remember precisely, so I think I should have a look to figure that out for myself, too. In any case this should be the notch for the timing light above 2725rpm.

Below a picture that confirms that there are in fact two notches above the F.

And thanks for the compliments! :)
Attachments
timing_marks.jpg
timing_marks.jpg (5.57 KiB) Viewed 6509 times
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

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Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: No ignition timing marks?

Postby Volker_P » Tue Apr 26, 2011 1:01 am

So I took apart the whole thing for a look and lubrication (which was necessary).
Seems like it is correct with the two F marks: left for light and and right for static/visual adjustment. There are obviously two more marks at the right side close to the advancer cam. Hard to see for sure when everything is installed. Following the scheme, I'd say one should see the left one with an ignition light above 2725rpm and use the right one when turning the advancer to full advance by hand.
But just my considerations, no written confirmation for that.
Attachments
Advancer_sm.jpg
Advancer_sm.jpg (49.65 KiB) Viewed 6924 times
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum


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