FE 501 2002 - Ignition Timing - Decomp - Starting Problems

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

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 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 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?