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pick up coil... (discovery)

13K views 13 replies 7 participants last post by  RICHW 
#1 ·
Ok guys...
First I have to thank Forchetto for a very good write up on the pick up coil matter...

My friend David have had some issues with a faulty coil on his 2001 Bonnie. leading to miss fire and alot of headache!

so we printed Forchettos write up and went out to the garage...

everything went as planned until we saw the pick up coil gap!!

se pic below!!!




thats NOT 0.8 mm !!!

close up....



hard to give a accurate view on the photo but the gap is approx 1.7-1.9 mm..............................


how can this be? loose bolts? idiot owning the bike before? etc etc


well now its adjusted and the bike sound better then ever before...


just a heads up :)
 
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#3 ·
Ok here is the question for the day the alt has like 3 trigger bumps the last one seams to line up with pickup coil some where around 5 deg btc.what logic does the ecm use to know when to fire ?Does it count leading edge pluss of the pick up coil or trailing edge?
What static timing does the bike have before the advance kicks in? How much do they very from one bike to the other as far as where they really fire at?
I bet some have as much as 2 deg more timing before the advance comes in then others.
I allso bet changeing the air gap can change timing some what. The lower the gap the sooner it fires if it works off the leading edge.If it works off trailing edge the later it would fire.Lets hear what yall think.
 
#13 · (Edited)
I have exactly the same concerns with the pick up coil. A 2001 came from the factory spec'd at 1.0mm+/-0.2 . Changing the gap to .08 allowed the POS Gill coil to properly "saturate". I suspect this retards the timing....with in the ECU factory timing tolerance. When I had problems in this department, I replaced the GILL coil with the Nology and left the pick up coil at 1.0 gap...the bike has been fine for over 50,000 miles since the update.

I suspect Triumphs change in gap spec is all about $$$. For a technician to swap a coil is about the same labor as readjusting the pick up. A coil costs a lot more money then a gasket, glue and a screw. Both "fix" the problem to most customers satisfaction...few if any will notice the difference of a degree or two has been dialed out...especially coming from a misfiring condition. I seriously doubt that the factory would advance the timing...this could result in higher emissions...

How the bike in this post ran AT ALL is beyond me.
 
#4 · (Edited)
I've been trying to get my head around this business of electronic advance/retard for years.

On igniter or CDI systems it seems it's done by delaying the signal received from the pick-up the appropiate amount.

The timing curves are stored on a microcontroller, something like one of those PIC16 MicroChip.
The PIC receives the signal from the pick-up and delays it by using an internal table. This means that the starting point of the ignition or the position of the reluctor is placed before TDC at the most advanced point in which you want to the ignition to work.

For the maximum advance, the PIC will introduce a zero delay to the received pick-up signal. It'll apply more and more delay to retard.

Be good if Pieman could explain this sometime though, I'm sure he knows how it's done.
 
#5 ·
you are getting real technical and i like to challange thy old brain...

after we adjusted the P.U.C it fired right up.. his bike have never been this easy to start!
and this is after sitting in my garage the whole winter.. first push = start

as Mikeinva says there is a lot of "play" on these coils.. the holes are alot bigger then the bolts that holds it in place so you can push it back and forth a bit..

how sensitive is this set up? i meen Davids bike worked with 1.7-1.9 mm!!

can his wrongly setup on the P.U.C thrashed the ignition coil?

many thoughts and many ways and means......

still its interesting discussing it! and I would love to know more about the subject :)
 
#7 ·
Mike: what happends when it fail? i know no spark is coming out but what fails in the coil?
 
#10 ·
Thanks for the info guys....

i have never thought about coils before.... if they work, they work :)

but now i know alot more....
 
#11 · (Edited)
I have just found this on my 2002 Bonneville too !!!

Bolts weren't loose either

My bike was never a good starter and I had put it down to other things so hopefully when all back together I will have a snorting fire breathing Hot Rod LOL
 
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#12 ·
Wow, nearly 2mm!

I'll add that when I opened my 2005 for the first time on that side to check the pickup coil gap, it was 0.8mm or possibly less--I had to push in the 0.8mm feeler gauge.
 
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