a (sort of) basic timing question

[interferencefit]

Are the GREEN coils 6V or 12V coils?
If they are 12V coils, you might hook them in parallel and get things to work!
Coil Resistance alone is insufficient info for us.
You said "The boyer unit puts out 6-7 Ohms," The Boyer unit might WANT to see 6-7 ohms of resistance in the coil, but WHAT voltage does it supply?
(BMWs want 6V coils in series for conventional ignition.)

Taking into account a fully charged battery (14.3 volts going in) and a current draw of 2.5 amps (I believe that this is correct at 500 rpm for the Micro Digital box, but it may be slightly higher) means that resistance greater than 5.7 Ohms at the coils will not allow the system to work correctly. This is my understanding of it anyway. 6V coils have less resistance than 12V coils (~1.5 Ohms vs. ~3 Ohms). If my problem is resistance-related then I could indeed run the coils in parallel, which I don't want to do, so instead I'll get coils with 1.5 Ohm resistance and connect them in series. It is my understanding that the only thing of import with a coil is the resistance. A "6-volt" coil just offers less resistance (which is necessary with a smaller incoming current from the battery) and can be used with a 6 or 12 volt system. Let me know if I've got this wrong, as electricity isn't really my bag.

[chasbmw]

I think that the Boyer micro needs 3ohms coil resistance , mine works fine with 2 dyn brown coils in series on a twin plug setup. The Boyer will also need resistor plug caps 5000 ohm ngks will do it. Otherwise electronic interference can upset the Boyersdigital circuits.
Boyers must be timed at full advance, set it on th F mark When the Boyer stops advancing, usually around 4000revs But this can vary, so use your eyes.

Don't worry about static timing, the tickover stabiliastion function of the micro digital , uses timing changes at around 800-1000 rpm, so if you put a strobe on the S mark , you will just see the S mark moving all over the place!

[Duane Ausherman]

Once you understand just how easy it is to static time it and how close it will be, do it as the starting point. You have painted the three marks with a dab of white paint haven't you?

Then with the strobe light, check the "S" mark just for another starting point. Do you have two marks and how close together are they?

Then go to the "F" mark. Even the "F" mark is also just one step. For ultimate running, then advance it until it pings and back of just that tiny bit.

If a person is going to mess around with tuning and especially ignition timing, then first learn how it works and what you should find and how to correct it.

Keep us informed.

[interferencefit]

Charles - I set up the system today with just one green coil (3 Ohms resistance). I fired both top plugs with that coil. I removed one coil so that the bottom plugs are just sitting there with no electricity coming in. I have the correct (5K) NGK caps. The bike didn't start so I can't set it up at 4,000 rpm.

Charles and Duane - The flywheel marks have fresh paint and could only be missed by a blind man on a galloping horse. I have only one "S" mark on the flywheel. I haven't used a strobe light yet, on account of the bike won't start. "F" has also not been useful to date, as the bike won't start (I did measure the distance from "OT" to "F" and it is 68mm; ~34 degrees). To set the Boyer initially, I rotated my engine to the "S" mark and then rotated the Boyer stator plate so that the magnets on the rotor were lined up with the metal tabs on the stator plate. No luck. So I rotated the stator plate in both directions (retard and advance) and still the same results, which are: definite flywheel rotation, good blue spark (at least when grounded to the heads), and fuel is definitely getting to the heads (after turning over for a while and removing the plugs to check for spark they were a little wet and smelled of gas), float levels are good and there are 24mm of fuel in each bowl when they are full. Should I set up the Boyer in a different way (not at "S") to get it started? Or, to phrase it another way, any ideas on what to do next?

[Jean]

do you have the original ignition parts?
By now, I'd have tried them...
TWO plugs, on top, with points, CAP, and either a pair of original coils or ONE of your 3 ohm double ended coils.
And...it's true: The 6 volt coils have lower resistance...but I wouldn't want to use "6-volt" coils on 12 volts as the current would go pretty high and they'd get hot, among other things, all the way thru the primary circuits!
Did it ever run to your knowledge, with the Boyer setup?

[Duane Ausherman]

If you have spark, then you can use the strobe light to see where the timing is.

You only need three things to run.
1. Compression, have you measured it?
2. Fuel
3. Ignition, at the right time.

I have been in this position a few times while working on a bike. It always turned out to be I was assuming something that wasn't true. It wasn't conscious, but none the less, I assumed.

Keep us informed, as this is getting interesting.

[bbelk]

Stick yer left thumb in the left hand spark plug hole. Stick the plug wire onto your pinky. Turn the key on.
Grab the back of yer rear tyre at the 2 o'clock position with yer right hand, and 'knock' the wheel in the forward direction.

I love it! If its still blowing air when your eyeballs light up, your spark is too advanced. If it is sucking on your thumb, like you may be after this test, your spark is retarded. If you actually run this test, you may be retarded as well.

[interferencefit]

If you have spark, then you can use the strobe light to see where the timing is.

You only need three things to run.
1. Compression, have you measured it?
2. Fuel
3. Ignition, at the right time.

I have been in this position a few times while working on a bike. It always turned out to be I was assuming something that wasn't true. It wasn't conscious, but none the less, I assumed.

Keep us informed, as this is getting interesting.

I have been thinking that it is time to check compression, although I doubt it will be too low. I have clean pistons, new rings, new heads (done by Randy Long), cylinders that were nikasil plated to match the pistons, and my heads are torqued properly. Gaskets are all clean and dry. I will check compression, as I was feeling that something must be pretty off, but I think that is unlikely to be the problem. I know what you mean about the obvious stuff (there's NO WAY that is wrong) being hosed.

Fuel is not a worry, yet. It is definitely getting into the heads.

I'm going to install the old points (which did run) and see if that does it (I'm a lot more comfortable knowing when the spark event occurs with points).

Also, I'm not sure what kind of RPM I'm cranking at, but can I just hook up the timing light and hold the starter button down and then see what happens in the window? I have never used a timing light on a non-running engine, but I suppose it's a good way to get in the ballpark in this situation. I can't get at the bike for another week and a half, but I'll let you know how it goes after I check compression and then do the timing with points. One man's interesting is another man's frustrating, although it is interesting, in an exasperating kind of way.

[chasbmw]

If the timing is anywhere in the ball park then the bike should start if everything else is OK.

Is the Boyer new? Did the bike run before you did the work to it?

As Duane says if you remove plugs and ground, then turn the engine over with the starter motor you can see what the static timing With a strobe.

There is a reason why with the microdigital Boyer should not be set on the static mark. You can see it on this advance curve graph, notice the V in the curve at around 800 revs.

http://i46.photobucket.com/albums/f146/ ... ngcurv.jpg

[Jean]

Cranking speed should not be an issue for starting and running.
Consider how "fast" cranking speed is when you use a foot-starter!
HOWEVER...if your starter is drawing a lot of current and the voltage drops below 9.5 or even 10 volts, the electronic ignition may not work.
When you crank with the plugs out, you are cranking without compression and just maybe that is enough to keep the starter current load low enough that the electronics DOES see it's minimum voltage..
...gas-wet plugs means no spark when you want it...
That it runs with the "points ignition" says something is WRONG with the electronic unit. It also suggests there's nothing wrong with the compression...or the valves.