How does the ignition work

[AUGIDAWG]

I have a 1995 Johnson 200.<br />Is the ignition timing fully mechanical?<br />Does the Power Pack over ride the spark advance anytime else then just when Quickstart is functioning?<br /><br />If my idle timing is 4 degrees farthur advanced at an idle than the spec, does that mean it is 4 degrees too far advanced during the throttle range, untill it hits the limiting WOT stop, or does the Power pack constantly control it depending on rpm or load, or both?

 

[Skyhigh]

Re: How does the ignition work

Your best bet is to get a SERVICES MANUAL.<br /><br /> http://www.boatmotors.com/manuals.html

 

[AUGIDAWG]

Re: How does the ignition work

I have 2 manuals.<br />The factory Johnson, and the Clymer.<br />They don't get that deep into how it really works.<br />They just say, "If that test fails, replace the,,,,,,,,,"<br />Or, in my case, "If the idle timing is not within these specs, go back and perform the link and sync operation from chapter two!"<br /><br />Someone here said, "Just set the idle timing with the screw, and it will take care of it's self."<br /><br />What does that mean?<br /><br />On a Ford, for instance, you set the static timing with a timing light, rotate the distributor, and plug the computer cable back in.<br />It does in fact, take care of it's self.<br />But, what I have seen so far with my Johnson, it is about equal to the old points and weights type of igninion, only without the points, and a mechanical linkage instead of weights. I don't even see any means of vacuum advance, so it is even more caveman than that. There is some kind of capacitance system, that advances during the "Quickstart", but other than that, there is no mention in the manuals of some other means of a "closed loop" advancing methode.<br />Simular to a eary model Briggs and Stratton.<br /><br />I'm sure one of you mechanics with 30+ years must know if there is sutch a system there.

 

[Hooty]

Re: How does the ignition work

The spark advance is all mechanical. The only time the electronics effect it is in S.L.O.W.<br />When adjusting full advance timing at idle or with the starter, you should deduct about 2* from the factory spec timing because of "lag" in the electronics.<br /><br />c/6<br />Hooty

 

[AUGIDAWG]

Re: How does the ignition work

I thought the WOT timing was 4 degrees different at idle. I like using the "no one at the wheel, 45mph, leaning over the chain saw, looking at white marks with a timing light, in the middle of the day" methode. Works for me.<br /><br />The timing from the power pack also changes when the "Quickstart" is active.<br /><br />So, if the timing is 100% mechanical, then if at idle, I am 6 degrees advanced (from the factory spec), then at 2000 rpm, I am 6 degrees too far advanced.<br />Correct, or am I wrong?<br /><br />The linkage has a shock absorber kinda thing on it. When you hit the WOT stop, which happens WAY before WOT by the way, the shock lengthens. But at an idle, the adjustment screw keeps the shock from getting shorter. So, as you move the throttle, the shock stays at the same length, until it hits the WOT stop.<br />Or, (this is what I'm trying to find out), something (like a vacuum advance on a old car) retards the timing by pulling on the shock, making it longer. Or, something in the power pack retards the timing, like it does during the S.L.O.W. operation.<br /><br />Is there any relationship between the rpm input to the power pack, and the output of the timing advance/retard?<br /><br />Anyone know?<br /><br />Anyone know someone at Bombardier that they can call?<br />This is a very intersting subject, and worth some investigation. (well, at least to me)<br /><br />Thanks.