Resin/Glue type substance on the ignition unit

Thread Starter

Autobike

Joined Feb 23, 2018
52
hello :) i've seen several motorcycles where their ignition units had some resin/glue type substance ( brown color almost like honey ) came out from the unit casing. they runs fine but i think it's something abnormal. one of my friends had the same issue with his TCI and the reason for that came out to be the faulty charging system (overcharging). so my question is,

1) what are the reasons for this issue ?
2) is that the heat which melts the resin/glue, eventually sweeps through the casing ?

thank you :)
 

shortbus

Joined Sep 30, 2009
6,973
thx a lot. sry for the late reply. seems very useful. will read it :)
Post #16 is the relevant one, kind of. Some of those old coils also had a wax in them to act as a dielectric. This was common on old bike coils, to keep them from destroying them selves if the plug got too fouled. With a badly fouled plug the spark would still try to find it's way to ground and spark over inside the coil shell. They thought the dielectric would help.
 

Thread Starter

Autobike

Joined Feb 23, 2018
52
Post #16 is the relevant one, kind of. Some of those old coils also had a wax in them to act as a dielectric. This was common on old bike coils, to keep them from destroying them selves if the plug got too fouled. With a badly fouled plug the spark would still try to find it's way to ground and spark over inside the coil shell. They thought the dielectric would help.
yea that link gave me a good idea. thx to @danadak
got it. i think same thing happens inside the TCI. is that the heat which melts the dielectric fluid ? thank you :)
 
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Thread Starter

Autobike

Joined Feb 23, 2018
52
luckly i found a cutaway of the same TCI which my bike (CBR250RR) has. this picture was taken from the net and the copyrights should go to its owner.

as we see here. it's kind of of a jelly type substance. may be the dielectric fluid as we saw on that post above. may be when the bike is overcharing, some heat generates inside the components of the TCI. so eventually it melts the dielectric.



thank you :)
 
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shortbus

Joined Sep 30, 2009
6,973
I forgot to mention another reason for dielectric in a coil or controller like that, heat removal. It makes a contact medium from the electronics(in your case) to the outside of the module, so the heat can get out of the internals of the module.
 

Thread Starter

Autobike

Joined Feb 23, 2018
52
I forgot to mention another reason for dielectric in a coil or controller like that, heat removal. It makes a contact medium from the electronics(in your case) to the outside of the module, so the heat can get out of the internals of the module.
thank you :)
 
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