Topic: Timing Question........Confused at Honda Manual

[dylboss]

So here are a couple of pics of my current timing by using a timing light.  The first one is a pic of the bike at idle.  The second is a pic at 2500 RPMs like the manual suggests.  I'm guessing this is off, but what do I do now?

Thanks!

http://flic.kr/p/9JcErm

http://flic.kr/p/9JcEN9

[MoMo]

Not advancing far enough, mark should fall between the two lines.  What is your gap?...Larry

[cookindaddy]

Just curious, if you go a bit faster, like to 3000 or 3500, do the advance marks line up then?

[dylboss]

Yes, if the RPMs go higher the lines match up.  Point gap is set at .016.  Valves have been set to spec according to the manual.

I guess I'm not sure if the 2 lines to the right of the number 4 should be lined up to the timing mark, or the 2 lines to the left of the "F" mark should be lined up.  Confused as to what is meant by "the 2 index lines 23.5-26.5 degrees before the F mark".  Also, if this is in fact off, which way should I turn the plate?  Sorry for my ignorance, but timing stuff spins me in circles.

[dylboss]

Sorry to be a moron and five year old intellect, but given the pics which way should I shift the plate?  Or,  what would be my next step to make the timing correct?

[Markcb750]

I believe you would find more success setting the timing with a test light or meter to detect proper timing, then using the strobe light to confirm correct adjustment.

If you have not removed and thoroughly cleaned the advance mechanism I would do that before setting the timing and gap again.  I use a thin (almost invisible) coat of a high quality lithium grease on the crank stub after cleaning to insure smooth motion. It should go to full advance before 2500 rpm.  You can check the correct maximum advance statically with the light/meter then again confirm proper operation dynamically with the timing light.

[Markcb750]

My strobing tool is just fine...I can get my wife to write you a note.

You must have a hell of an "eye"  to tell when the points have just lifted...

[Markcb750]

Using a lamp/meter is how the factory service manual instructs one to proceed, must be all the Honda personnel had #$%*ered eyes.  They use a Strobe as a redundant check.   

I do not know why Honda choose to instruct people to proceed this way, but I do remember Hank at Ayers Honda using the Honda meter in the early 70's on my 72 cb500 four.


It is not nice to pick on Presbyopia People.  You will be here someday yourself. 

[dylboss]

Right now the F mark is lined up with the fixed timing marks at idle.  If I move the plate to adjust for the advanced marks, won't I mess up the current setting at idle, since the F mark is where is it supposed to be? I adjusted tha gap on the points already, so I know that is correct.

[Markcb750]

Dylboss

If I understand you correctly:  The timing at the advance line should be reached as you increase the RPM reaching full advance a little before 2500 rpm.  If the advance is off There is a spring adjustment in the Honda service manual available on the website.  I would suggest removal & cleaning in a good solvent prior to adjustment of the springs as indicated in the manual.

Mark

[dylboss]

Thanks Mark.  Which manual are you referring to?  I have the CB550 Workshop Service Repair Manual, but I can't seem to find the advance timing adjustment section.

[dylboss]

Here is another pic I took when the RPMs were climbing into the 3s.  How would I adjust the advance mechanism stops?


http://flic.kr/p/9JqrQu

[Markcb750]

the manual is a little vague, sorry I had not looked at in a while.  The springs should be made a little looser if you are sure the system is not advancing quickly enough.

[dylboss]

 Well, according to the last pic I posted, it seems that it might actually be advancing too much.  The advanced lines are going beyond the fixed timing lines, and rotortiller says there is a way to adjust the stopping mechanism.  Just wondering how to do that as well now.  1 step forward and 2 steps back....

[dylboss]

I'd say that you need rotate the big 1/4 master timing plate to line up the advance marks and the F mark going from these as both are out in the same direction by similar amounts...correct on the pics?

http://www.flickr.com/photos/62978085@N02/5728422510/#

http://www.flickr.com/photos/62978085@N02/5730916576/#

Ok.  I'll try that tonight and post my results.  Thanks.  I appreciate the help.

[seanbarney41]

If your timing is advancing too far/too fast it may not be a problem...it is only a problem if you experience preignition, detonation, or pinging (the pinging is the resulting sound of one or both of the first two)...but be careful!...Detonation can not always be detected by ear...you have to check your spark plugs...any good plug reading chart will give pictures of what detonation does to your spark plugs   this is also happening to the tops of your pistons.  I would set your initial timing spot on then road test listening for pinging, check spark plugs for signs of detonation...if none is found I wouldn't even worry about the advance being off.  Here is a link to a plug reading chart...
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

[dylboss]

If your timing is advancing too far/too fast it may not be a problem...it is only a problem if you experience preignition, detonation, or pinging (the pinging is the resulting sound of one or both of the first two)...but be careful!...Detonation can not always be detected by ear...you have to check your spark plugs...any good plug reading chart will give pictures of what detonation does to your spark plugs   this is also happening to the tops of your pistons.  I would set your initial timing spot on then road test listening for pinging, check spark plugs for signs of detonation...if none is found I wouldn't even worry about the advance being off.  Here is a link to a plug reading chart...
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

Thanks Sean.  I'll definitely try that. 

Here's an update on my findings tonight.  Pulled the base plate off and advancing mechanism, cleaned the mechanism (was definitely dirty).  Put everything back on, adjusted timing for 1 & 4.  Spot on.  F mark is where it is supposed to be when at idle, and at 2500 RPMs the advance lines are perfectly lined up with fixed timing mark and wouldn't go too far no matter how high the RPMs went. 

Now on to 2 & 3.  There's always a gotcha somewhere.  Timing was definitely off here.  I moved the plate for 2 & 3 all the way to the farthest right it would go.  Tested it and the F mark was just a hair off (literally, like a mm), but advance lines were going too far beyond the fixed lines at 2500 RPMs.  Not sure what to do here, or if it even matters as you say Sean, because I have no more adjustment room on the 2&3 plate in the direction that it needs to go.

[MoMo]

You will need to reset the point gap on 2/3 so the fire mark and advance falls into place.  Gap may be different that 1/4 but it is what needs to be done.  First , put the plate in the mid position, set the gap and check timing. If moving the plate does not line up the fire and advance you will then need to fudge the gap.  Anywhere from 12 to 16 will work as long as the marks line up...Larry

[Spanner 1]

If everyone took apart their advance units and cleaned 'em we'd have a lot less poor running SOHC bikes with guys 'setting' their timing with advancers stuck 'open'..... IMHO 

[Markcb750]

If everyone took apart their advance units and cleaned 'em we'd have a lot less poor running SOHC bikes with guys 'setting' their timing with advancers stuck 'open'..... IMHO 

Irishman self-named after adjustable nut removal tool speak truth to daboss.

[Spanner 1]

 

[dylboss]

You will need to reset the point gap on 2/3 so the fire mark and advance falls into place.  Gap may be different that 1/4 but it is what needs to be done.  First , put the plate in the mid position, set the gap and check timing. If moving the plate does not line up the fire and advance you will then need to fudge the gap.  Anywhere from 12 to 16 will work as long as the marks line up...Larry

That seems pretty straight forward Larry.  I will try that.  Thanks.

[seanbarney41]

If everyone took apart their advance units and cleaned 'em we'd have a lot less poor running SOHC bikes with guys 'setting' their timing with advancers stuck 'open'..... IMHO 

I remember when I first got my 750 thinking, "What a waste of cc's, my 360 would smoke this pig."  Then I discovered my advancer was stuck at the idle advance.  As soon as I unstuck it, I discovered a whole new world of motorcycling!

[dylboss]

I have to say........people are pretty gracious on this forum unlike a lot of others.  Still very much a newbie with vintage bikes, so I do appreciate the help and biting of the tongue that I've been experiencing.

[seanbarney41]

I'm just happy your taking your time to learn how your points work and not just dropping $200 on electornic ignition ...which half the time, those sort of people still can't get to work right!