Topic: Dyna S Timing---Are my advancer springs worn?

[elquenada]

I double checked my Dyna-S timing this morning.  I timed it statically as described in the instructions and then I put a light to it.  For some reason Im lined up at the advance marks regardless of rpm.  I wrote an email to Dyna to make sure this was wrong; he it was and suggested that maybe the advancer springs were worn and staying open all of the time.

It seems to make sense but I'd love some more input.  Has anyone here experienced this as well?

[Gordon]

Turn the ignition rotor clockwise with your fingers.  It should snap back into place by itself.  If it doesn't then you have an advance mechanism problem. 

[elquenada]

it does snap back when i manually turn the rotor.  I know cause thats how I set the static timing.

[Gordon]

it does snap back when i manually turn the rotor.  I know cause thats how I set the static timing.

That's kinda what I figured since you said you static timed it by the Dyna instructions. 

I don't know what to tell you.  Does the rotor turn freely from its resting position to full advance and then back?  Does it stick at all in the advance position?   

[markjenn]

I assume you know that on the Dyna S, you're always supposed to time in "full advance" (whether done statically or dynamically) and that after you do so, the non-advanced timing won't line up to the F marks like it would with the stock points?  (I've always found this odd - doesn't it make the idle timing less than optimal?)

- Mark

[Frostyboy]

The way I look at the instructions from Dyna, is to ensure that no claims can be made against them for engine damage related to too much advance.
If the dynamic timing at idle is too high after setting by their instructions, perhaps it's time to replace the springs on the advance plate?
I'm not sure of their availability but the specs for a 550 at least are 1.43~1.87lbs. Unfortunately I can't find a specified length.
Start of advance is @ 1150rpm with full advance of 25 degrees @ 2300~2500rpm

[Gonzowerke]

A quick dogpile search found this thread on this very forum;
http://forums.sohc4.net/index.php?action=printpage;topic=40133.0

You can only get them as part of the complete advance unit. Like ZX12R, you can remove one end and twist it 1/2 turn in the tighter direction and see where that gets you.

Gonzo out.

[elquenada]

thanks for all the help; i really appreciate it.

Mark as far as what you said:           

I assume you know that on the Dyna S, you're always supposed to time in "full advance" (whether done statically or dynamically

Im confused, are you saying that it should never line up against the F mark?  I did time the unit to full advance but I thought I would still see the F mark line up at idle.  Isnt that how it goes? 

[Frostyboy]

I think it means that if you do the timing dynamically, you should set it to the full advance mark with the engine running above (for a 550) 2500rpm. I believe  the concern is to ensure that it's not subject to too much advance.
I guess that means you may not see the F mark at idle, depending on how strong those springs are.
If advance starts at 1150rpm you'd have to be idling under 1000rpm to see the F mark.
[Edit] I've rethought the way I was looking at that full advance setting.
I think now it means that max advance is achieved.
If the timing was set dynamically at the F mark, and the springs had already started to move, full advance wouldn't be achieved.

[Ace]

I've finally worked out a problem I've been having with my CB750 F2.  Due to humid conditions, the arms on the mechanical advance unit had corrosion where it fits on the dowel and then the circlip is put on to stop it from coming off.  This is the second time I've had this problem, every 2 years it seems (I can't believe I got done in by the same problem).  I could turn the rotor and it would go back, no snap or anything.  Not convinced so I pulled it apart and a bit of surface rust was there not allowing easy movement of the arm.  This caused the mechanical advance system not to work properly and I had a flat spot mid range.  I did other engine mods and put it together and I just thought it was the cam characteristics being a hot street/strip cam.

Took it all apart, cleaned up the corrosion and put a little bit of grease on the arms and away we went.  Still have a slight flat spot but I think that is related to needle position in the carby.

My CB750 K1 has dyna ignition and is timed statically, lined up on the F mark and works great.  Goes to full advance within specs while running and back to the F mark at idle 1000rpm.  The CB750 F2, I had to advance the timing due the cam, so at idle 1000rpm it is timed to the right of the F mark (where the marker is in the case, advanced timing).  I had to do this dynamically to get best performance for the cam.  Idles good now as well.  The following is an extract from a previous thread of mine from my experience.

The instructions for installing the dyna ignition are not the best.  I static time my bikes and set it up on the 'F' mark on both 1/4 and 2/3.  Then I run the bike and check it with a strobe at about 3000rpm which is on full mechanical advance and it lines up with the advanced marks on the plate and the mark on the engine case.

Setting it full advanced either by static timing or by strobe idling is setting yourself up for trouble.  Been there done that.  Bike backfires through carby, starting problems, idle problems.  However, when you get up the revs to where your engine operates on full advanced you have no problems.  The further you advance your timing, you will reach a point where you will not get any better performance out of your bike and the EGT rises and your pipes will start to change colour.  Blue does look nice on some occasions.  You can advance your timing beyond what it recommended if you are not running a stock engine for example different cams.  I've also seen a CB750 run better with the ignition timing slightly retarded and go like a rocket for a stock engine.

Always set your timing up on the F mark initially and then check that the timing marks for full advanced line up with engine running with about 3000 rpm (two vertical lines to the right of the F mark).  You can adjust as required from there.  I'm not saying leave it always on this as sometimes you can get better running and performance by either retarding or advancing the timing.

If you set your timing on the F mark by either static or strobe and find out on full advanced that the marks don't line up, you may have a problem with your mechanical advance unit.  I had this problem so no matter where I set the timing, that's where it stayed.

[markjenn]

Im confused, are you saying that it should never line up against the F mark?  I did time the unit to full advance but I thought I would still see the F mark line up at idle.  Isnt that how it goes?  

Well, it doesn't on mine.  The Dyna S instructions never tell you to use the F marks for anything - whether static or dynamic, they say to use the advanced marks, either revving the engine to 2500 for the strobe method, or rotating the rotor by hand to the advanced position if using the static method.

I only used the strobe method and when I set the advanced marks, the F marks don't line up at idle like they would with the points ignition.  My advancer seems to be working fine and the bike runs fine, although the idle is not quite as smooth as I remember a new bike might be - I've always attributed this to 40-yo carbs.  I asked about this on this forum many moons ago and was told this was completely normal with a Dyna S, although I don't understand why since the difference between idle and 2500 RPM spark should be completely due to the mechanical advancer.  So I remain puzzled about this.

- Mark

[elquenada]

  I asked about this on this forum many moons ago and was told this was completely normal with a Dyna S, although I don't understand why since the difference between idle and 2500 RPM spark should be completely due to the mechanical advancer.  So I remain puzzled about this.

- Mark

well i must say im confused with you.  My bike is running ok and the problems I do have I believe to be due to my coils.  When I get that figured out I may revisit this issue.

thanks to everyone for the help.

[bistromath]

My Dyna S times just-a-hair ahead of the F mark at idle and sits perfect between the advance marks @ 2500. So it does work sometimes....

[Spanner 1]

An awful lot of work and worry for no advantage over the stock ignition....IMO.... same mechanical advance is in play, and Dyna S is ' one size fits all ' with no compiance to the ' factory' spark advance curve on our bikes, right?, or is Dyna make/model specific??

[kos]

One thing I have noticed about this and many other forums. Everyone "over thinks" every problem all the time.

Dyna S

Make sure battery is charged, Install rotor on GOOD advancer. ie: must be free to move (advance) and springs must be strong enough to snap back.

Take the plug out of #4 cylinder head location and lay on top cover. Turn on ignition switch rotate engine clockwise until you see spark at tip of number 4 plug. STOP there!

Now, look at marks through the hole on timing plate and see where you are as far as aligning with "F" mark with indicator on engine block.

Keep repeating until you have spark at "F" mark.


YOUR done!

Go ahead and try this...and I will guarantee your bike will run perfectly.

WE won Daytona 7 times and 5 National Championships with a a Dyna S and I have never used a timing light!

Don't try and over engineer these things. WASTE OF TIME (me sorry...no pun indended!)

KOS

PS: if your are not running some awfully high compression ratio, like over 11/ to 1 and are on special fuel or something this will be the ticket.

[Gordon]

An awful lot of work and worry for no advantage over the stock ignition....IMO.... same mechanical advance is in play, and Dyna S is ' one size fits all ' with no compiance to the ' factory' spark advance curve on our bikes, right?, or is Dyna make/model specific??

This thread is not typical of most Dyna-S installations.  People come here to get help when they're having a problem installing something, not usually when the installation went smoothly, so you get a skewed perspective. 

[HondaMan]

Several times over the years, I have come across the problem you're describing with the Dyna S.

Most of the time, it was due to the gap between the little magnet in the rotor and the pickups themselves being too small. First, check that gap. Old Dynas with the blue PC board backplate have a smaller gap than the newer (metal) ones: check your instruction sheet for that gap.

Second, I have seen several Dynas where the cam with the magnet has too big a hole in the center, which lets the darn cam wander about on the advancer's center post and even jam the advancer. The solution to those was to get another cam from Dyna: they cooperated when the units were under warranty, sending a new one that was made properly. I have seen this 4 times.

Third, if the unit is running the 3-ohm Dyna coils and there are no series resistors with those coils, the triggers may have been overheated at some point. This makes them "leak", electrically speaking, and they will default to an overly advanced state as soon as they warm up. When cold, they will often time OK at the "F" marks, but as soon as the engine heats up the plate, they go to an advanced setting because they are never actually turning all the way OFF for spark, and trigger too soon. This cannot be adjusted out.

This last failure mode happened to mine, twice. The first time was after they were used with 3-ohm coils for a few weeks: the second time was after a very hot trip: I got the unit secondhand from the owner and it failed shortly thereafter.

If you have a current meter (many multimeters have a CURRENT input mode), set it to 10 amp mode and connect it in series with one of the Dyna triggers, right in line between the trigger and the coil. When the bike is cold, turn on the key (and RUN switch) and make sure the magnet is in front of that trigger: take the current reading. It should be very low, in the milliamps range. Then run the bike until it warms up the plate. shut off the engine, then turn the key back on, make sure the magnet is pointing at the trigger being tested, and re-measure that current. It should not change more than 10%. If you find that it has jumped to about 100 milliamps (0.1 amp), then that rigger is leaking: it is damaged. Repeat with the other trigger. That's the best non-Dyna test I can suggest: it has been a reliable way for me to diagnose the bikes that show up here with those troubles.

[Spanner 1]

Yeah Gordon, your right !...... I just saw an opportunity to diss Dyna ignitions( again ), rather than try to help the poster, my bad.
IMO, I just can't see any advantage over stock.... but open to enlightenment, which I have never seen so far......

[bistromath]

Third, if the unit is running the 3-ohm Dyna coils and there are no series resistors with those coils, the triggers may have been overheated at some point. This makes them "leak", electrically speaking, and they will default to an overly advanced state as soon as they warm up. When cold, they will often time OK at the "F" marks, but as soon as the engine heats up the plate, they go to an advanced setting because they are never actually turning all the way OFF for spark, and trigger too soon. This cannot be adjusted out.

Interesting failure mode, Mark! I've been running 3-ohm Dyna coils on a Dyna S for 4 years, and mine still seems fine. Did you ever see this failure on the new (metal back) Dyna S? I wonder if they improved the transistor or heat sink situation.

[HondaMan]

Third, if the unit is running the 3-ohm Dyna coils and there are no series resistors with those coils, the triggers may have been overheated at some point. This makes them "leak", electrically speaking, and they will default to an overly advanced state as soon as they warm up. When cold, they will often time OK at the "F" marks, but as soon as the engine heats up the plate, they go to an advanced setting because they are never actually turning all the way OFF for spark, and trigger too soon. This cannot be adjusted out.

Interesting failure mode, Mark! I've been running 3-ohm Dyna coils on a Dyna S for 4 years, and mine still seems fine. Did you ever see this failure on the new (metal back) Dyna S? I wonder if they improved the transistor or heat sink situation.

The new metal-backed ones seem to hold up better than the older style, especially with the 3-ohm coils. I've seen more failures on the K0-K6 bikes than the "F" bikes, which I attribute to most of the older bikes also having the older Dynas. But, since January this year, I have seen 3 of the newer steel-plate type Dynas here that died: two had 3-ohm coils and one had stock Honda coils. Go figure. 

The Dyna engineer I first queried about the 3-ohm question in the 1980s said those Hall Effect triggers were rated for a maximum of 4 amps at 180 degrees (or maybe it was 200 degrees, I'd have to go look up my old notes), which corresponds to running 3-ohm coils if the voltage at the coils is 12 volts. Fortunately, it is usually lower than that, around 10.8 volts when running. Otherwise, the poor triggers are running at max all the time. The engines run about 210 degrees on a hot summer day in that area (on the cases), so it's pretty close to max.

Since the 1980s, the backplate changed to steel instead of PC board, and the triggers themselves received some heatsinking enclosures. Oddly, though, the devices inside are still the same ones. Higher-current Hall Effect triggers are available today, so I'm not sure why they haven't been implemented. But, speaking from an engineer's perspective: many companies won't bother with improvements if the warranty costs are below some "magic" threshold of dollars. 

[Gordon]

IMO, I just can't see any advantage over stock.... but open to enlightenment, which I have never seen so far......

You say you're open to enlightenment on this topic, but I don't really believe you.  We've gone back and forth on this a number of times, and not even reasoned arguments seem to get through.  I know an aftermarket ignition isn't going to be the absolute best, most perfect thing there could ever be for every person's bike and in every situation, but on many bikes and for many people it is.   

[elquenada]

thanks for the current testing info Hondaman.  I'll check that out this weekend.

[excerpt]

One thing I have noticed about this and many other forums. Everyone "over thinks" every problem all the time.

Dyna S

Make sure battery is charged, Install rotor on GOOD advancer. ie: must be free to move (advance) and springs must be strong enough to snap back.

Take the plug out of #4 cylinder head location and lay on top cover. Turn on ignition switch rotate engine clockwise until you see spark at tip of number 4 plug. STOP there!

Now, look at marks through the hole on timing plate and see where you are as far as aligning with "F" mark with indicator on engine block.

Keep repeating until you have spark at "F" mark.


YOUR done!

Go ahead and try this...and I will guarantee your bike will run perfectly.

WE won Daytona 7 times and 5 National Championships with a a Dyna S and I have never used a timing light!

Don't try and over engineer these things. WASTE OF TIME (me sorry...no pun indended!)

KOS

PS: if your are not running some awfully high compression ratio, like over 11/ to 1 and are on special fuel or something this will be the ticket.

Heading to the garage RIGHT NOW.