ignition advance on SEM

Taffy · Jan 22, 2008

just wanted some discussion on a subject that i will be lost on after the word "the ..........."!!!

but i called sparks sunday night and we got chatting about the advance curve on the SEM.

what ideas have people like bundy and oyk got about a programmed ignition curve but still using the SEM?

regards

Taffy

Parsko · Jan 22, 2008

Taf,

Are you suggesting changing the curve but using the exiting SEM? AKA, replace the ignition box with another one?

-Parsko

Taffy · Jan 23, 2008

yes exactly!

the ignition advance is in the coil (somewhere!) and a coil is a coil as far as i'm concerned so is there a way of having the ignition adavnce put somewhere where it can be adapted and the coil does it's task seperately?

'conny' at the SEM factory has offered to modify the original which i presume would be without smashing/breaking the coil open.

what a shame lineaweaver isn't here to tell us how much he has put into the vortex ignition system?

regards

Taffy

mikey4410 · Jan 23, 2008

sounds very technical !!!!!!! and involved

BundyBear · Jan 23, 2008

I think the really old ones (last century?) had an analog spark curve control circuit - just resistors & crap. Even the bloke who originally designed it would probably baulk at trying to change the curve at will.

The later ones - certainly since Digital Force? - have the spark curve programmed into read-only memory on a microcontroller. Infinitely more configurable and infinitely harder to change for anyone except them who have the gear like the original mapping equipment.

Makes you miss flyweights & springs!

Taffy · Jan 23, 2008

then what about something outside this area?

is there not something out there that can be played with and plugged?

regards

Taffy

sparks · Jan 23, 2008

Taffy said:
then what about something outside this area?

is there not something out there that can be played with and plugged?

regards

Taffy

Like I mentioned Taffy I our tel conversation like the Sherco and Beta digital CDI it you know where to remove a small amount of the potting you can uncover the four terminals required for reprogramming but you need the computer soft wear to go with it.

When I was working with the Sherco (sorry to use the swear word) ignition you have a small box about the size of a cig packet which can hold four programs so when you are out in the field on a trial you can quiet easily change the curve characteristics to suit the trial or section..
But if you were working from the computer direct to the CDI the amount of curves you could use was infernet.

Regards

Sparks.

Parsko · Jan 23, 2008

Re: RE: ignition advance on SEM

Taffy said:
'conny' at the SEM factory has offered to modify the original which i presume would be without smashing/breaking the coil open.

Please get more info on this!!! I'm curious to see one of these things less the potting. Any one of these, old or new. If you give me time (and I'm talking about in months, not days or weeks), I would like to do the same thing for my '91 (as I have suggested many times in the past).

If you can get 'connie' to separate the coil from the trigger/curve, I can eventually replace the trigger/curve part of it. I've been trying to figure out the coil part, the rest is easy!!! Also, any insight as to what the curve might look like would also help. Again, I've been trying to figure out the coil part of the CDI units, the rest is cake (relatively). If you can get a spare unit, and don't mind waiting, I'll paypal you for shipping!

-Parsko

JoeUSA · Jan 23, 2008

Re: RE: ignition advance on SEM

Parsko said:
Taffy said:

'conny' at the SEM factory has offered to modify the original which i presume would be without smashing/breaking the coil open.

Click to expand...

Please get more info on this!!! I'm curious to see one of these things less the potting. Any one of these, old or new. If you give me time (and I'm talking about in months, not days or weeks), I would like to do the same thing for my '91 (as I have suggested many times in the past).

If you can get 'connie' to separate the coil from the trigger/curve, I can eventually replace the trigger/curve part of it. I've been trying to figure out the coil part, the rest is easy!!! Also, any insight as to what the curve might look like would also help. Again, I've been trying to figure out the coil part of the CDI units, the rest is cake (relatively). If you can get a spare unit, and don't mind waiting, I'll paypal you for shipping!

-Parsko

Use a dial back strobe tach like described in Dale Lineaweaver's post.

You can map the actual timing of the spark relative to top dead center at any rpm .

Joe

http://www.husaberg.org/index.php?name= ... =dial+back

Dr_C · Jan 23, 2008

RE: Re: RE: ignition advance on SEM

Off-topic, but anyhow: On early BMW F650Ã‚Â´s ignition modules, there was the possibility to choose from 7 different ignition curves. You just connected one cable to earth over a specific resistance (correct word?). Each resistance value had a corresponding ignition curve, and I mean different shapes of the curve, not just the advance. Pretty handy, me tinks. I used it on my old Yamaha TT600-engine, together with a tiny flywheel and a total loss system.

Taffy · Jan 23, 2008

RE: Re: RE: ignition advance on SEM

Mat

well there could be a few bob in it for a man who can design an ignition curve that's futuristic! my point now would be that with the wires going into the coil -and there are a few - then we should be able to get something.

regards

Taffy

Parsko · Jan 23, 2008

RE: Re: RE: ignition advance on SEM

Joe,

I'm not suggesting finding out what the curve is. I'm asking to see the bits that sit between the trigger wire from the SEM and the trigger input to the coil. AKA, what is the crud that doing the reading of the trigger, performing some timing calculations based on RPM, and telling the coil to fire?

-Parsko

PS - I just noticed a Lineaweaver in present company...

Magnusson · Jan 23, 2008

RE: Re: RE: ignition advance on SEM

Taffy,

I got a modified SEM to my -02 650 to match the engine they did for me.
And, there was some difference to the standard unit.
No difference between HI/LO at all, but with that carb and FP exhaust there was some serious Lean-out pops.(Loud ones with 20cm flames)

I got more torq in the low range

and more over rev.

Taffy · Oct 7, 2008

RE: Re: RE: ignition advance on SEM

i'm getting different readings with every SEM unit. i've done one today that appears to ****** before finally advancing through to 25d BTDC at it's maaximum adjustment.

i was advancing the strobe and then whacking the throttle.

nothing was in sight?

just like that scene out of the battle of britian!!! nothing was on the ops table and in their words: "the *******s are up to something!".

nothing was on the radar.

i even had glowing exhaust headers at 12d BTDC (full advance).

so i've run out of adjustment.

to be honest - every bike is different. just recently i haven't had to half the advance to get the real figure. this could be my snap - on strobe playing up but i know that it isn't! it's that i'm getting some ignitions which my strobe recognises as what it is is what it is.

like isay - everywhere. i do think some of it is the HT lead as well though. i've fitted the strobe clip over tape and a revcounter wrapped wire in the past and it altered the timing to all over the show. so is this the answer?

regards

Taffy

sparks · Oct 7, 2008

Re: RE: Re: RE: ignition advance on SEM

Taffy said:
i'm getting different readings with every SEM unit. i've done one today that appears to ****** before finally advancing through to 25d BTDC at it's maaximum adjustment.

i was advancing the strobe and then whacking the throttle.

nothing was in sight?

just like that scene out of the battle of britian!!! nothing was on the ops table and in their words: "the *******s are up to something!".

nothing was on the radar.

i even had glowing exhaust headers at 12d BTDC (full advance).

so i've run out of adjustment.

to be honest - every bike is different. just recently i haven't had to half the advance to get the real figure. this could be my snap - on strobe playing up but i know that it isn't! it's that i'm getting some ignitions which my strobe recognises as what it is is what it is.

like isay - everywhere. i do think some of it is the HT lead as well though. i've fitted the strobe clip over tape and a revcounter wrapped wire in the past and it altered the timing to all over the show. so is this the answer?

regards

Taffy

Hi Taffy,

Not sure why you are getting all these different ignition readings, the cdi/coil I use for testing is from a 650 and does as you described it ******* slightly before going fully advanced, but all the stators I run give the same curve, but there is three different boxes that have different curves, but all the stators and flywheels are stamped up the same.
Regarding the tacho wire wrapped around the lead this could be giving off some spurious inductance that is throwing things out.
Some ignition systems that I run up have to have the HT cap fitted to suppress the spurious harmonics if not the spark on the degree disk goes haywire.
When you say every where can you be more Pacific?.

Regards

Sparks.

Taffy · Oct 7, 2008

RE: Re: RE: Re: RE: ignition advance on SEM

pacific? that's a real fen word that is!

i can imagine a war film where you're asked to repeat a sentance with it in and the bad guys get shot just for saying specific.

anon.

some ignitions advance smoothly, others ****** before advancing, some flutter so you get to see your white mark at each end of the window at the same time. they can literally just disappear. you don't know whether they are ******** or advanced waaaayyyy beyond or infront of the window.

i noticed that as i advance the ignition the revs linger longer before settling on a few. this might explain some of the so called carb problems.

ask away steve. when i'm doing it though i am on such borrowed time. you can't rev a bike to 6k with it sat still, no air and quite frankly....not a lot of water moving either! so i really don't spend ages doing it. i tend to run it up and then go off and make a call/loo/cuppa/whatever etc etc.

regards

Taffy

sparks · Oct 8, 2008

Re: RE: Re: RE: Re: RE: ignition advance on SEM

Taffy said:
pacific? that's a real fen word that is!

i can imagine a war film where you're asked to repeat a sentance with it in and the bad guys get shot just for saying specific.

anon.

some ignitions advance smoothly, others ****** before advancing, some flutter so you get to see your white mark at each end of the window at the same time. they can literally just disappear. you don't know whether they are ******** or advanced waaaayyyy beyond or infront of the window.

i noticed that as i advance the ignition the revs linger longer before settling on a few. this might explain some of the so called carb problems.

ask away steve. when i'm doing it though i am on such borrowed time. you can't rev a bike to 6k with it sat still, no air and quite frankly....not a lot of water moving either! so i really don't spend ages doing it. i tend to run it up and then go off and make a call/loo/cuppa/whatever etc etc.

regards

Taffy

Hi Taffy,

Ok so you must of gone to a better approved school than me, English grammar was never one of my strong points, the word is spelt correctly but in the wrong context.

I would guess the unevenness is due to the uneven running of the engine at lower rpm, when run up on the rig the rpm is always dead steady no fluctuations.
The test coil I use starts to advance at around 3750 and when it hits 5000 jumps 10 degrees instantly then you get smooth advance then the slight ****** before fully advancing.
But some other cdi's I've checked start to advance from around 2000rpm.

If the revs are lingering slightly before settling down to idle sounds like it could be a bit on the lean side.
That reminds me your last words, time for a brew.

Regards

Sparks.

Taffy · Oct 8, 2008

RE: Re: RE: Re: RE: Re: RE: ignition advance on SEM

i can understand the engine getting stuck at that point where it's meant to advance more. lets remember that after firing a single cylinder engine slows rapidly before the next firing stroke.

if you're going to speak proper fen you also have to add sustificate to your vacabulary. only then along with webbed feet will you qualify. as for wehat you did with your sister i don't wanna know but it would qualify you further!!!!

seriously though, i'm sat here with a bike that's on 25d BTDC and it's on maximum adjustment. although you try to understand the problem i don't think there is anything else to say but that the coils are shyte like the stator units.

my first customer had a horrible coil on it. and his bike just sits there going pop, pop, pop, popo, pop, pop all the friggin time. i have mentioned him before to you some months ago.

perhaps next time i'll give you a one-on-one account of each one i check.

regards

Taffy

BundyBear · Oct 8, 2008

Was reading the Trailtech manual last night & it talks about some ignitions putting out more pulses-per-rev (sparks per rev?) when the engine runs over a certain speed.

What the hell is this and does it apply to any 'berg stuff?

sparks · Oct 9, 2008

BundyBear said:
Was reading the Trailtech manual last night & it talks about some ignitions putting out more pulses-per-rev (sparks per rev?) when the engine runs over a certain speed.

What the hell is this and does it apply to any 'berg stuff?

Hi Brad,

I've seen this twin spark set up on the RM Suzukis, They run a second spark about 3 or 4 degrees infront of the main firing spark, but goes to a single spark at around 4000 rpm.
I think it to get better combustion at the lower rpm range, but the Husaberg ignition doesn't have this, would be interesting to test one out on a Berg though

Regards

Sparks.

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