1972 45hp Chrysler - No spark from bottom plug

[Jan Svade]

What is the best way to check if a spark plug lead is producing current? I only have spark at the top cylinder but it is strong and even enough to run the motor. I have a mini tacho that wraps around the plug leads and reads the RPM. This reads on both leads, so unless it is reading off the top lead the bottom lead may have current and the boot may be faulty?? Both plugs are ok as I have swapped them and the top lead sparks with both plugs.

Is there a way to replace the boot without replacing the lead, as the coils are under the flywheel.

Thanks.

 

[tater76]

Re: 1972 45hp Chrysler - No spark from bottom plug

Most likely is a bad condensor, and yes these will run well on one cylinder. I doubt you have a local NAPA there in Australia, but just in case.. the part # is FM200. Try swapping condensors and test for spark, that will tell you immediately.

 

[Jan Svade]

Re: 1972 45hp Chrysler - No spark from bottom plug

I have not had a chance to remove the flywheel to check the condensors, but I reversed the ignition wires at the terminal block and the spark moved to the bottom cylinder and no spark at the top cylinder. Sorry to not understand the ignition system so well, but can anyone tell me what this could point to?

 

[tater76]

Re: 1972 45hp Chrysler - No spark from bottom plug

You need to pull the flywheel and inspect your points and condensors. One of the two is what is causing your no spark situation.

 

[Jan Svade]

Re: 1972 45hp Chrysler - No spark from bottom plug

Problem solved. The previous owner had attached the earth wire to the blue ignition wire instead of the slot below marked EARTH. I switched the wire across and bingo both cylinders spark. Now to take it out and see if I can reach higher RPM. Thanks for your replies Tater.