Iirc this kit was about 10 bucks at Amazon. Hey... ya never know when you might need a resistor. 
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Programmable advance TCI Replacement
- Thread starter 2XSive
- Start date
OK, someone check my theory and execution. I marked the leading and trailing edge of the trigger advance coil on the back of it for easy viewing. Transferred those marks to the stator.
Then I transferred the TDC mark to the stator. I did that so I could remove the existing pointer. I wanted the degree wheel to lay flat.
Then I overlaid the degree wheel on the stator.
From TDC to the leading edge of the coil is 99°
I'm gonna call that plus or minus about 2°... just based on possible transfer errors.
Everyone cool with that?
Then I transferred the TDC mark to the stator. I did that so I could remove the existing pointer. I wanted the degree wheel to lay flat.
Then I overlaid the degree wheel on the stator.
From TDC to the leading edge of the coil is 99°
I'm gonna call that plus or minus about 2°... just based on possible transfer errors.
Everyone cool with that?
It looks good to me. I must confess I had to reread it a few times as I missed the LE and TE marks referred to he trigger and not the coil.
Any transfer errors could be corrected by slotted pick up mounts as per 5 Twins mod.
Edit:
Transmic posted while I was writing.
From his info the easiest method to me looks to align the leading edge of the pickup and magnet.
Any transfer errors could be corrected by slotted pick up mounts as per 5 Twins mod.
Edit:
Transmic posted while I was writing.
From his info the easiest method to me looks to align the leading edge of the pickup and magnet.
Last edited:
>From TDC to the leading edge of the coil is 99°
You are measuring the distance from TDC to the pickup coil. OK it's 99° it’s a partial bit of information, it doesn't give any number to WHEN the coil is excited by the magnet/reluctor on the rotor relative to TDC.
Using the stator only is not enough. Or perhaps I got you wrong… sorry then
You are measuring the distance from TDC to the pickup coil. OK it's 99° it’s a partial bit of information, it doesn't give any number to WHEN the coil is excited by the magnet/reluctor on the rotor relative to TDC.
Using the stator only is not enough. Or perhaps I got you wrong… sorry then
It looks like the original TCI box used the trailing edge of the trigger coil.
When I set the rotor TDC mark at 40° btdc, the magnet falls just on the trailing edge of the advance coil.
When I set the rotor TDC mark at 40° btdc, the magnet falls just on the trailing edge of the advance coil.
Another pair of eyes?
@TwoManyXS1Bs
@TwoManyXS1Bs
So, if I put the leading edge of the magnet at the leading edge of the advance coil, the difference in the stator and rotor TDC marks is 56°
That should be our value, correct?
Correct! To nitpick a bit
post 307: The center of the magnet is at 209.
If the rotor turns CCW the center of the magnet touches the leading edge of the coil at 261-209 = 52° and it leaves the pickup at 252-209 = 43°
The first pulse @52° is the one we wanna use and the second one is 43°
The first pulse can be positive or negative depending on the wiring.
post 307: The center of the magnet is at 209.
If the rotor turns CCW the center of the magnet touches the leading edge of the coil at 261-209 = 52° and it leaves the pickup at 252-209 = 43°
The first pulse @52° is the one we wanna use and the second one is 43°
The first pulse can be positive or negative depending on the wiring.
As a shadetree guy, I know nothing of scopes and waves and such, my observation tells me these electronic events tend to happen when the magnet just leaves the pick-up: math = 42* by my cypher'in, but I'd start at 40* just for GP
No, first... we're looking for the leading edge, not the trailing....As a shadetree guy, I know nothing of scopes and waves and such, my observation tells me these electronic events tend to happen when the magnet just leaves the pick-up: math = 42* by my cypher'in, but I'd start at 40* just for GP
My math says 56°.
Thierre's math says 52°
I'll split the difference and input 54°.
Leading edge/trailing edge is not a problem. Things can be physically adjusted for how it works. What's important is how stable it is.
How about putting a timing light on the degree wheel when it's making sparks?
A few odds and ends....
First, the pickup type is definitely a "type 1 PN". Auto (0) says the last type sensed is a type 1. If I select type 1, it sparks as it should at 250rpm. If I select type 2 NP, I get nothing. So I think we can safely say type 1 should be selected.
I can't get the "Bypass" function to operate. I get nothing at 250, 500 or 1000rpm. It's like the box isn't even powered up.
I tried resetting everything with the "/INITALL" command but it didn't make any difference.
With my rather crude measuring setup, inputting 55° for the trigger position was showing me right at TDC at 250rpm.
Default advance for 500rpm is 5° and that's exactly what I saw. I didn't try and add any advance values for higher revs.
I ran it in "Console" mode and it more or less agreed with that. 250rpm on the drill press gave us 286rpm and no advance.
550 on the drill gave a readout of about 575 and right at 5° of advance.
All this was done with a .085" air gap and an 8kΩ resistor in the divider circuit.
Yeah... calling it "crude" might be a little on the kind side.
First, the pickup type is definitely a "type 1 PN". Auto (0) says the last type sensed is a type 1. If I select type 1, it sparks as it should at 250rpm. If I select type 2 NP, I get nothing. So I think we can safely say type 1 should be selected.
I can't get the "Bypass" function to operate. I get nothing at 250, 500 or 1000rpm. It's like the box isn't even powered up.
I tried resetting everything with the "/INITALL" command but it didn't make any difference.
With my rather crude measuring setup, inputting 55° for the trigger position was showing me right at TDC at 250rpm.
Default advance for 500rpm is 5° and that's exactly what I saw. I didn't try and add any advance values for higher revs.
I ran it in "Console" mode and it more or less agreed with that. 250rpm on the drill press gave us 286rpm and no advance.
550 on the drill gave a readout of about 575 and right at 5° of advance.
All this was done with a .085" air gap and an 8kΩ resistor in the divider circuit.
Yeah... calling it "crude" might be a little on the kind side.
So, FWIW, with "un-resistored pickup", in Console Mode, set-up at 40* and Advance set to 13* above 800rpm, the igniter was sensing 16* @1160rpm, but the strobe was flashing the rotor mark at the drain groove - all back on page 5, post #86
So, FWIW, with "un-resistored pickup", in Console Mode, set-up at 40* and Advance set to 13* above 800rpm, the igniter was sensing 16* @1160rpm, but the strobe was flashing the rotor mark at the drain groove - all back on page 5, post #86
Would/could that be due to the difference in location of sensor (your 40* setup vs the 52 -56 it looks like it should be)?
