Topic: 750 with old 3 ohm coils

[jakec]

I have this 750 I want to get running which has these old crusty Dyna coils which are marked 3 ohm. The plug caps on the wires looked really poor and weren't fitting to the new plugs well, so I installed an old set of caps left over from my 400 rebuild.

I tried to start the bike and wasn't getting anywhere. Just wondering if mixing the 3 ohm coils with the caps off the 400f (5 ohm resistance type, I think). I am also using resistorless plugs (D8ea).

[gtmdriver]

3 ohms is the resistance in the primary coil windings and doesn't affect the resistance in the secondary high tension circuit. 3 ohms is correct for ignition systems using contact breakers. Are you using resistor plugs along with suppressed (resistor) plug caps? That might be a bit much if the rest of the system is marginal.

[jakec]

I am using resistor plugs and non-resistor caps. The type of setup that has been on my 400 and 550. I just have never seen or used 3 ohm coils so I was wondering if the combination was going to cause a problem.

I haven’t done anything besides what’s mentioned in the original post, so there are many other factors to why it wouldn’t start. Just  wanted to rule this one out!

[madmtnmotors]

I am also using resistorless plugs (D8ea).

I am using resistor plugs.

 

[jakec]

Sorry, I was on my phone typing that. to clarify I am using RESISTOR type CAPS and NON RESISTOR type PLUGS (D8ea).

[Don R]

 Stock coils are 5 ohms, these has been discussion whether 3 ohm coils tax the charging system. I wasn't able to check the coil. wire and caps together because my meter wouldn't measure it until I took each part off and checked that way.