Mystery backfires/ignition 180 out???

Jim

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While you're at it ohm out the plug caps, SHOULD be 5K ohms, can be about anything 40 years on.
Caps or plugs need to be the 5kΩ resistor variety... but never both. 5k caps and non-resistor plugs, or 5k plugs and non-resistor caps.
I'm currently running the non-resistor caps and 5k plugs.... mainly 'cause the resistor plugs are easier to find right now.
 

Team Junk

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For our children's children in the future when this thread is resurrected.

The only safe way to use the points coils on a TCI is to wire them in series instead of parallel. That puts the coil resistance at around 5 ohms which the TCI should be happy with.

Probably a good idea to carry a spare Gonzo and pigtail for when the TCI box takes a dump. Size and weight of a pack of cowboy killers.

Glad you got it sorted and good info to know about the stock TCI.
 

Jan_P

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Yes sounding like a parrot again
Yamaha had a points ignition setup with their coils In house with part number
Going TCI .Big companies usually have a standardization department .. trying to keep down the numbers of components
So it would be a natural first question

" Can we design the TCI so we can use the same coils ? "
and the answer seems to be NO
Not 100 % certain there can be other factors involved fex the TCI designer and subcontractor can have an order
FIX this..
and refusing to deliver anything else than the design they do and take responsibility for
Perhaps wanting to sell the Col also.
Install and forget .

That is a risk --> when the TCI box takes a dump.

$ 100 box fried and $ 200 tow + the long walk to find help


Also the risk that at full rev the TCI " Loosing it " .Smashing a puls Knocking at the wrong time .Preignite . We can be talking a new engine in worst case. Some cases perhaps not XS 650

I understand that cost is a factor . And I am all for looking to save some money but electric and especially electronic systems are matched. It can work but many tines it dont
 

atom4488

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For our children's children in the future when this thread is resurrected.

The only safe way to use the points coils on a TCI is to wire them in series instead of parallel. That puts the coil resistance at around 5 ohms which the TCI should be happy with.

Probably a good idea to carry a spare Gonzo and pigtail for when the TCI box takes a dump. Size and weight of a pack of cowboy killers.

Glad you got it sorted and good info to know about the stock TCI.
Team Junk,
Not sure how would the coils be wired in series? If the TCI has a single trigger output, and each coil has a single trigger input, what does a series circuit look like?
I bought a generic Gonzo box to try, so I'm gearing up in that direction. I have a spare TCI as well.
 

5twins

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When you wire stuff in series, don't the resistances simply add up? The points coils are rated at around 4 ohms so that would give 8 ohms total. I'm thinking that would be too much for the TCI. It was designed to use a coil rated about 2.5 to 3 ohms. It may push through that 8 ohms and spark but I'm thinking that spark may be weak.
 

Jim

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When you wire stuff in series, don't the resistances simply add up? The points coils are rated at around 4 ohms so that would give 8 ohms total. I'm thinking that would be too much for the TCI. It was designed to use a coil rated about 2.5 to 3 ohms. It may push through that 8 ohms and spark but I'm thinking that spark may be weak.
The TCI box wouldn't have a problem with 8Ω. If anything it would make life easier on the transistors that trigger the coil.
However...... 8Ω at 12v cuts the current all the way down to about 1.5A
Would make for a very weak spark at the plugs. Maybe even too weak to work.
 

Splodge

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I would like to get hold of a faulty set of pickup coils to tear apart with a view to making copies but no one this side of the Atlantic has anything, I really don't want to destroy a good set.

I've wound guitar pickups in the past, the principle is pretty much the same except on a bike they would need to be water proof, heat proof and vibration proof, potted in resin instead of wax, making bobbins and housings isn't a problem for someone with a 3D printer.:cool:

I'm now thinking towards using hall effect devices instead of pickup coils, with an interface box which converts the Hall Effect trigger signal to something the TCI understands.

The downsides to that are that the Hall Effect devices need a power source, that would probably involve fitting an extra wire down to the pickup, plus the interface box would be an extra thing which can go wrong at the roadside.

Me and my son, (who is much more clever than me with electronics), are currently working on a direct copy of the TCI, most of the compononts are easily availible but there are some unidentified diodes on the board so it's going to take some measuring, swapping and testing to find equivilents for them.
TCI-Kicad.jpg


I'm currently working on building a test rig which will have an inner spinning disc with an embedded magnet which is driven by a brushless model plane motor with variable speed control, an outer stator disk marked with, (virtual), TDC and degrees of advance, using real coils and spark plugs I will be able to to use a strobe to look at and plot the timing advance curve from the workbench.
So yes, there are people out here doing stuff, it keeps the brain from going the same way as the creaking bones.😃
Neil
 

Jim

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I would like to get hold of a faulty set of pickup coils to tear apart with a view to making copies but no one this side of the Atlantic has anything, I really don't want to destroy a good set.
I've got some bad ones if you want to pay the shipping. Postal code is 64118 Mo. USA.
You know the weight and dimensions so if charges aren't too outrageous. it's yours.
 

Splodge

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Hi Jim
that would be really great, you can cut the wires off, down to half inch or so, that should keep shipping down too.
If I PM my address to you would you be able to find out how much shipping would be?
A big thank you to you :thumbsup:
Neil
 
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