What kind of relay do people use for coil repower?

Hey guys, I am getting my 1978 KZ400 back in shape. My ignition coil secondary winding was broken (even though I still had spark) so I bought a new one. I also noticed that I only get 10.5-11 V at the coil low voltage side, therefore I thought to go for the coil repower mod to have the full battery voltage at the ignition coil.
I noticed that people use regular automotive electromechanical relay for this mod and...aren't this relays too SLOW for such application? A straight-twin at 2000 RPM is firing approx 30 times per second..regular automotive electromechanical relays take at least 15-20 ms to go from off-on-off.. shouldn't I use a REED relay or a solid state relay? Am I overthinking this?
Thanks !

I'm using a off the shelf auto parts relay. They only have to switch on and off the power to the coils.
Steve.

Go to wiredgeorge webside for more details

wgcarbs.com/index.php/using-joomla/exten...-categories/89-coils



Get power form starter relay bolt connected to the battery cable !!!

SWest wrote: I'm using a off the shelf auto parts relay. They only have to switch on and off the power to the coils.
Steve.

So the relay is always ''on'' as long as the bike is on! Got it! I thought that the trigger for the relay would be the points signal, this would have caused the relay to cycle on-off 30 to 50 times per second, which I believe is too much for an electromechanical relay.

Scirocco wrote: Go to wiredgeorge webside for more details

wgcarbs.com/index.php/using-joomla/exten...-categories/89-coils

Get power form starter relay bolt connected to the battery cable !!!

Thank you, the diagram made me realize that the trigger signal is the constant voltage coming from the ignition that was previously powering the coils NOT the points signal.

I've done this mod myself, but I still think it's important to point out that you are not fixing the problem, but instead are wiring your way around it. FWIW it has worked great for me and the old KZ starts up flawless every time.

I've used this mod on almost all of my bikes and it always helps. Starting and cold / wet performance is better. I do bolt a spare relay right next to the one I add for this mod but I've never had a relay fail.

80B4 wrote: I've used this mod on almost all of my bikes and it always helps. Starting and cold / wet performance is better. I do bolt a spare relay right next to the one I add for this mod but I've never had a relay fail.

That's a great idea! They are cheap and I have had one fail, but I think it was my fault.