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1985 Honda: No spark, starter turns strong, get gas and new plug

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I have a 1985 Honda, Big Red. No spark, starter turns strong, get gas and new plug? Any suggestions?
What have been tested so far?
Hi and welcome to JustAnswer,

Initially, check for the presence / absence of:
  • IGN + 12 at the black wire going to the CDI (ignition switch to ON and when cranking);
  • if none, check for battery + 12 on the red wire at the ignition switch or the ignition switch itself;
  • if there is, then check for a low pulsating ACV on the blue / yellow wire going to the CDI from the pulser coil;
  • if there is, then check for a high pulsating ACV on the black / red wire going to the CDI from the exciter coil;
  • if there is, then check for a high pulsating ACV on the black / yellow wire going to the ignition coil from the CD;
Presence of voltages on the red, blue / yellow and black / red but none on the black yellow would indicate a faulty CDI (most likely) or ignition coil (least likely). To determine which, temporarily float / disconnect the black / yellow wire going to the ignition coil from the CDI and measure if there is a pulsating high ACV when cranking:
  • if yes, then it would be a faulty ignition coil;
  • if none, then it would the CDI.

Please post back results of initial tests.

Good luck and thank you for using JustAnswer.
Customer: replied 8 years ago.
What is a CDI and where is it located?
Appreciate the postback.

A CDI is capacitive discharge ignition and its purpose is to take triggers from the pulse coil, amplify the output of the exciter coil and in the correct time discharge the voltage on the ignition coil. Basically, it replaced the contact point / breaker & condenser of older engines.

It would look something like the image below.

graphic

To my recollection, it would be under the tank held by rubber cushion / clamps.

Louie and other Motorcycle Specialists are ready to help you
Customer: replied 8 years ago.
Thank you, XXXXX XXXXX looked at both of them , and I am about to leave for a couple days. I'll accept you answer as not to hold up your monies ( I hate waiting to get paid)...LOL)Thanks again,

Joe D.

Customer: replied 8 years ago.
Thank you, XXXXX XXXXX't looked at both of them , and I am about to leave for a couple days. I'll accept you answer as not to hold up your monies ( I hate waiting to get paid)...LOL)Thanks again, Joe D.
Many thanks for the ACCEPT and would look forward for updates on how things turned up.

Cheers.

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