bigd764

This is a diagram of the coil according to service manual.My original coil looks like this. My new coil isn't marked with + or - . So i hooked it up with the green/white wire directly across from the spark plug wire.

55 minutes ago, Mech said:

As for having the coil either way around..  That's not so. The primary and the secondary windings both attach to the same internal earth. If it's connected the wrong way around the HT instead of earthing straight to that internal earth, has to go through the primary windings to get to earth..  That HT burns through the insulation on the windings.

It has to have the internal earth end of the primary windings going to earth..

Since the new coil doesn't have the + and - terminals marked,how do i determine which one is which?

Thanks. I will try that tomorrow and post back with the results.

The lowest setting i have on this meter is 200 which i think is not low enough.

On 2/22/2023 at 10:29 AM, Gwbarm said:

Primary coil resistance .18-.28 ohms, secondary resistance 6-9 K Ohms.

Thanks. The primary resistance i get is .000 and the secondary is 10 K Ohms.

On 2/20/2023 at 10:55 AM, Gwbarm said:

Just had another bad aftermarket coil out of the box, it wasn't completely bad but specs were not what they were supposed to be for my machine. 

I tried testing the resistance on the coil. Could you tell me what the specs are supposed to be?

The replacement coil was much smaller in size than the original. I had to drill holes in the mounting plate to get it to bolt up. It's mounted securely and i don't think vibration is the issue. It has two wires and i am not 100% sure they are reverse connected. I took a look at the service manual and it said the bike would run with the wires either way without changing performance. The original coil was marked with positive and negative terminals but the replacement was not.

First of all, thanks for the replies. The coil is an aftermarket and i know they are cheaply made. It's hard to find an OEM for this old ATV without paying a big price for it.

Oh, by the way, it has a new battery, spark plug, Cdi, and regulator-rectifier.

6 minutes ago, bigd764 said:

I have a 1989 Bayou 300 and  i have to keep replacing the ignition coil on it. Does anyone know what might cause this ? It runs great for a few weeks and then it just stops firing and won't start back until the coil is replaced. I have put 3 new coils on it already.

I have a 1989 Bayou 300 and  i have to keep replacing the ignition coil on it. Does anyone know what might cause this ? It runs great for a few weeks and then it just stops firing and won't start back until the coil is replaced. I have put 3 new coils on it already.