CDI lesson......

[Vmax540]

Finally, got a chance to fire up a 1983 540 that I got this summer. Good spark and fuel supply and all it would do was fire every pull and after checking all connections and adding new plugs had the same result. Switch out the CDI and Tyler pulls one time and she came to life ! Switched back to original CDI and had the same one fire results so we reinstalled the new CDI and once again she came to life. So, when checking for spark with the original CDI I thought it was a blue spark but, sort of thought it was possibly not overly spectacular so, I am thinking it would be best to get a spark tester and maybe one that you can adjust to see just how wide a gap it will jump and therefore just how strong is voltage from the ignition. http://www.jrgraham.com/itemdetail.do?a ... tg=7108930 Let's hear everyone’s thoughts !

B.T.W. we had a 540 with the same one fire no start symptoms and found loose connections down where the stator harness plugs from the engine into the main wiring harness. Right (Modsingle) ? ! ?

[vmax-540]

The 83-86 Vmax's had about 18,000 volts ,the 87-91 had different stators and CDI's and had about 28,000 volts.
Don't forget the CDI has advance curves and other circuits in them so it may be possible to get good spark by pulling it over ,but if the advance curve circuit or one of the other circuits is bad it may or may not be firing it at the right time. If I were you and you have it running with a different CDI then I would just leave it alone and maybe check some of the CDI shops to see if they can rebuild the bad one..

[modsingle]

Yep, loose connections and then within 100 miles the box went out of it. Now I have a different box and runs great.