FE 501 2002 - Ignition Timing - Decomp - Starting Problems

Hi

Never used this kind of programmable ignitions.

One strange thing that I've noticed looking at your pictures is that you have chosen the option of one fire per revolution ?? That is a 2T.

Don't know if that makes any difference ? but it can

At idle we usually consider 6º deg of advance.


ZAGA

Hi,

thanks zaga, I was also wondering about that - but I did not set it up like this - it was read via cable from the CDI. So I assume the parameter was set by the previous owner.

Other options are possible, as in the picture below.

In a Husaberg brochure from 2002 I found this implied/draft of 2 ignition curves, but no numeric values. Too bad... ...pic an brochure below

Hi

I yes I have that brochure but unfortunately that graphic is for marketing purpose only.

My doubt with that option remains since I don't know if that will really influence the CDI or if that is just to ID your programme ??

When I was playing with the kokusan ignition to fit it in my bike, a got some advices from Paul Tinwel, that knows a loooot more than we do about ignitions.
His advice was to keep the max advance at 40 deg, to be safe. So that would be my advice to you.


ZAGA

Also

From my experience, I can only see a noticeable difference between the 2 curves if you set it at idle correctly, if not, it will be already too advance to notice the difference. Except it will not rev so high.

Also, some people say that the graphic is not correct and the difference will be only at max advance. I think the problem is what I've described above, but not sure ??

You have the perfect tool to play with this, you can easily make a couple of experiences and try to replicate the curve of that graphic.

I would set the idle advance at 6 or maybe 5 deg for good starting and go from there.

It should be a fun toy have, your ignition.


ZAGA

Thanks Zaga,

the bike came with this type of ignition and I could never really ride it, since it always stops running with backfire when approaching higher revs. So I need to check it, to make sure there is no mistake in the ignition timing. Otherwise I'll brake the bike or my bones :unsure:

Since I'm not an expert on ignition timing, I want to collect as much information as possible, to figure out if there is something that has to be changed or not.

Putting things together that I have so far. Hardware first:

1. Flywheel - o.k. (no loose magnets, or whatsoever)
2. SEM-stator with common stator defect: Pick-up coil o.k., charging coils broken
3. Replica stator: Horse Power Ignition ST5410L (seems to be the same as the Electrex one)
4. Used Husaberg CDI from 2003, OEM-Part-No.: 250-293-01 / 855-191-14
5. Ignitech-DC-CDI inductive coil

Hardware drawbacks:

• SEM-stator: I cannot check the stability of pick-up signal at high rpm - engine is not running
• ST5410-stator: no ignition timing mark
• Husaberg CDI (855-191-14): Don't know if functions correctly - bought second hand
• Ignitech-CDI: don't know if kids manipulated the ignition advance map

I thought about testing two configurations:
A) SEM-stator + Ignitech-CDI + Ignitech inductive coil
B) ST5410-stator + Husaberg-CDI/coil

Setup A) requires correct ignition advance map values. Therefore here comes the guess-work

Rev-Limiter
Starting with the rev-limiter value, which in my case is 9.700rpm on curve A and 15.000rpm on curve B. I assume the FE 501 Husaberg won't rev higher than 10.000rpm. If so, I would not force her to do so. ZB00P once posted a plot from his dyno-run in the forum (year 2000 FC501), where the plot doesn't reach the 10.000 (see picture 1). Let's take this as a starting point for setting the rev-limit below a little less than 10.000 (picture 2).

Ignition-per-Revolution
I guess here I have to set it to "1 ignition per 2 revolutions (camshaft)". Sounds to me as the onliest 4-stroke mode here - but I don't know anything about since the documentation has no info about it.

Ignition Advance Curve
Basically there is three curve shapes possible (see picture 3), but I assume only options - linear and degressive - make sense in ignition advance. All curves I found so far look actually degressive. So besides all theoretical information about ignition advance, this might be the basic curve shape to go with (even the data from the Husaberg brochure I posted looks degressive). Based on that I assume that ignition timing advances less with increasing rpm.

The Ignitech-CDI interpolates linear between two sampling points. The better I want to meet a certain curve, the more sampling points I should store in the CDI. Therefore I guess ignition advance between the first two sampling points looks like the green dottet line in picture 4.

Base Advance
Currently is set at 10°. When I understand the concept of base advance correctly, It is the the difference between the end of the metal strip passing the the pick-up coil, measured in crankshaft degrees (see picture 5 below). This distance is defined by hardware and can only be changed by rotating the stator. So when putting the engine in TDC and using a new flywheel mark and adjusting the stator to the new mark, the base advance has changed - it's not the "default" anymore. Since many guys figured that when the engine idles the ignition timing should be about 6° BTDC - I assume this is my new base advance for the CDI. Is that correct?

Sampling Points
I guess that the ignition advance sampling points usually are set manually by try and error procedure on a dyno with online control for fuel-air-ratio. My aim is not getting the last horse power out - it's rather to get it running at all
From what I read/know about ignition advance is that most engines have a maximum advance between 32...36, up to 38...41. When I compare that with the data stored in my Ignitech CDI, which (Curve A) is 39° at 4.000rpm, 41° at 5.000rpm and still increasing up to 47° at 9.000rpm, my feeling is that there is something to much advanced... (see picture 6). Besides that it seems also strange to me, that between 5.000-8.000rpm the advance curve changes its shape from degressive to progessive -- same as between 1.000-3.000rpm.

Anybody out there that could give me some advice on this one?

Hi

As far as I understood you only have problems at high revs, no problems with starting and running at mid revs ??

You have a very long post so I will try to follow and tell you my opinion.

If possible to start I would like to use the original configuration (stator+CDI), but I understood you had to rewind your stator, if that is what you want let know, I might help you with that. About the CDI, usually they are good or they are broken, so if you test it and it makes a spark, my guess it's that is good.

I've never tried, but when using the HPI or the Electrex stator (the same), you can try to make your own timing mark based on the original SEM (sending you a file). I presume that will give you the same starting point as you have with the SEM.
I've read Taffy saying that with HPI/ELECTREX you should go to the max retarded position ?? because it will be too advanced ??

And yes, at least with the SEM configuration, you should set the advance at idle at 6º

Regarding the ignitech

I would play with it, as you say you don't want every HP your engine can give, so I would start with a more conservative curve.

Set the advance at idle at 6º and the max at 36º and rev limiter at 9000, and you don't have any problems, if you set the stator at the correct advance at idle.

As you say the program will interpolate points, so those steps that you have will be smoother, also the more points that you add the smoother will be the curve. The old SEM coils jumps from idle advance to max advance in an instant and those engine still run

The only thing that worries me is that you might be using a too big max advance and if you rev it long and hard you might destroy your engine.

Also be sure that the problem doesn't come from anywhere else.


ZAGA

Hi Zaga,

thanks so much. Saturday night I could install the engine in the bike. I made a short test with the electric starter. The auto-decomp works fine now. The engine produced a few puffs. Feels like I'm on the right way - a few puffs is more than before

I'll try to work on it next weekend again. Thanks so much also for the pdf - I'll also try out the electrex/hpi stator - I'm just curious about it.
For the Ignitech ignition advance curve - I'll try a conservative curve first

Update:

I found a screenshot of the Ignitech-Software-Interface used at FP-Engineering showing some ignition advance curve data (picture attached). With this info, a rough guessing for the map curves from the brochure and the data from my Ignitech device I generated a plot (picture 2):

• Red curve displays the data found on my Ignitech device
• Green curve represents the data from the Husaberg brochure
• Black curve is the data from the FP-Engineering screenshot

Looking at the curves clearly shows that the map points from my device have significantly different base advance and also the rise is more steep.

I'll try then with the lowest curve (HBG-brochure-Curve-B) first...

Hi

I don't know how its going on right now with the electrex stator, but there were problems in the past with them, burning CDI's

So my advice is to try it with the ignitech that I presume it would be less sensitive ???

There is also a theory, that I've never tested, about the protection of the CDI against peaks of power. If you find the right diode it won't be a problem.
I'm sending you a doc of what I imagine it should be, but again never tested. I've not even seen one electrex in person

For the new curve I would just keep this numbers in mind, 6º base advance, 36º max advance, 9000 max rpm.

Good luck

ZAGA

the Electrex are fine Zaga, seriously!

we have now sold 40 or so and had no trouble. we had a review yesterday over costs and prices and we have put up the SEM rebuild costs considerably as we have been losing £5 on each one when sold in the EU on ebay and that can't continue as you can imagine.

we were the first to put up a question mark on ebay and in the shop but now it is clear to me that they are OK.

just to put you right on sdomething you said the other night: you said that i had "retarded the Electrex fully to the max' (I ad lib here) just to get it right.

yes i used to!

but now I retard all the way and come back 1mm (at the circumference) and they are just about right everytime. what is difficult is the fact that your TARGET; the static white line-has gone!

so now you just have to "imagine" the middle of the hole...

regards

Taffy

Taffy

As I always said, I never used one electrex, so for me it's always ear say.

If you now say they a fine, it's fine by me.

Just 2 questions:

I didn't understood how do you set up the advance, do you make a timing mark on the stator, or you imagine one ? Maybe not so easy !

And in your opinion is the electrex better then the sparks rewind or is just cheaper ?

Thanks for the info

ZAGA

nothing in it Zaga. we have had more of sparks fail straight away under confusing circumstances but then be 100% fine afterwards or for all the others. Electrex are fine but the conduit takes up less space in the rubber bung and needs lots of silicon or water will definately get in.

yes, i imagine the middle with my strobe!

Taffy

Hi ede

I've just made here one exercise with the ignition curve from the brochure.

I'm not saying that it accurate or even true, but if it were, it would be a much softer curve that you have

It was just to have some fun


ZAGA

Hi Zaga,

here's the update: The bike is running again :spin:

Thanks goes to you and Taffy for helping me (and of course to everybody else who's posting helpful stuff). How did I solve it? After reading Taffy's post about the Electrex it decided for setup B)
Electrex stator + Husaberg rotor + Original CDI (Husaberg Part. No: 250293-01)

First I tried with your 45° setup from "SEM MKII Timing Mark Position.pdf" but it didn't work. Then I tried Taffy's method - rotated the Electrex fully to the right (max. retarded position) and afterwards about 1mm to the left again. Pressing 3 times the start button and the baby runs again!

So I was wondering why your 45°-method doesn't work - in the first place it makes sense to me... but here's my thought:

When I saw your drawing - the 45° were measured from the center of the pick-up-coil. I guess the voltage in the coil is induced when the metal strip on the flywheel starts approaching the coils edge. Like on the picture below - there will be an offset - crosscheck it with the 6° before TDC method - the offset looks to me like the difference between the two ignition marks on the flywheel...

I guess when you fully retard the Electrex - it's about the same.... just a thought... I'm curious about it since I would like to figure it out in detail

Hi Zaga,
I read your Voltage Limiter document again.

Is there any practical/user-reports about the setup using a Z-Diode between the red and the black wire?

I'm not a specialist for things with electrics/electronics - but after a discussion with a friend, questions arised.

1. What voltage signal the CDI expects? Alternating or directed?
2. What's the maximum voltage the CDI can handle?
3. What's the maximum current the CDI can handle?

My assumptions/questions:
Between the green and black wire the CDI expects alternating voltage. The proposed Z-Diode then will limit the voltage one way. Due to the Z-Diode current-voltage characteristics, the z-diode will open in the other direction way earlier (e.g. 0,7V) and therefore increases the current drastically. I'm concerned the high current could kill the CDI. Could that be?

What Do you think about Z-Diodes connected in opposite direction to limit both ways?

Hi

First, let me tell you this is a theoretical set up, as I've told you, I never had one stator of this brand.

Second, Taffy has been saying that this problem has happened with the early ones and now he has sold a lot without any problems

Now let me try to answer your question, this was a thing for the red wire, not the green, no problems with that one.

The red will charge the coil and the green will give the signal for the spark timing.

The red should give around 300 VDC max to the coil, but it works with a lot less, it will depend on the rpm. If you put a 230V transformer it will work just fine.

The red already has one rectifier diode that will make a half wave rectify (only using the positive side of the wave) because the coil is like a battery, it can only store DC power.

That other diode (on the red) would work as safety valve, if the current was too high, it would drain it to the black (earth).

Anyway, taking in consideration Taffy's experience and that your bike is running without a problem, I wouldn't worry too much.

Hope I've made some sense, if not let me know.


ZAGA

Hi again

About the other post that you've made, the one with about the different position of the stator.

That is the green wire thing

As a magnet goes near a coil, it will induce a current, like the one on the picture. Depending on the orientation, it will start the wave as it approaches, to one side, and to the other side as it goes away.

Your CDI will "listen" to that, and will interpret it. There you can have some more variables, with more or less complex systems. Then it will give a "response" that will be the firing timing.

So if that coil on the electrex is a bit different, it will produce a slightly different wave, and maybe that is the reason why the position of the stator needs to be different ??


ZAGA