no spark

[never21]

i have a 1974 yamaha mx 125, a few months back i got it running but needed a new throttle cable now that i have the cable i am having problems with the spark. i checked and i have spark all the way to the coil, but after that nothing. i dont know what to do. should i just replace the coil?
thanks

 

[schmanman]

so you replaced the throttle cable, and it quit sparking?

I'm guessing the two arent correlated, since the wiring and cables are not connected.

so if you have spark before the coil, and not after the coil, then it would seem the coil is bad. but, my knowlege on electrical systems is very limited, so I would wait for another opinion before I did anything.

 

[never21]

sorry i didn't mean to say the cable and coil were related. but i had spark before and now i don't. im pretty sure i need to replace the coil but i was just checking for a second opinion or maybe someone who knows better than me.
if i need to replace the coil does anyone know where i can get it? getting parts for this bike has been a real pain.

thanks for your help

 

[Uchytil]

Do a search for coil testing, you'll find a wealth of information. You'll need a multimeter to conduct some testing. If you find no path on the plug wire you may have a loose/disconnected boot which sometimes can be repaired.

 

[schmanman]

www.bikebandit.com

www.denniskirk.com

do a search on dennis kirk by MMY.