CX500 GL500 650 Global

Thanks for the quick responses. Before i replaced the coils, when the wires melted, i had tried swapping just the coils and still no difference. I will try again on wednesday to swap the coils. I dont know what the CDI or TI is but i did replace the wiring harness.

Also, i will check for a spark, though last time i could not see one.

Thanks for everyone's help with this very frustrating problem,

-WIll

Sorry I thought it was a CDI.Anyway what you say about the plug cap is what I was trying to say.Even recently as last week I put my spare CX on the road I had this problem and when I raised the plug cap away from the engine with a pair of insulated pliers and held it near the top of the plug the cap arced across and the cylinder fired.I knew then the cap was a dud so bought a couple of new ones that I fitted last week from Wemoto,

http://www.wemoto.com/bikes/Honda/CX_500_A/79-80/

I always buy the none resistor type as I don't see the need these days for the AM radio interference resistor type and also as it's common that people use the wrong plugs on their bikes e.g the originals were D8ES-L none resistor not the DR8ES-L(Used in Canadian models tho') I don't see the point in having two resistors in the circuit and I like less contacts in the caps to go wrong.
My UK 1980A and I think the 78/79 were the same and used the D8ES-L and none resistor plug caps.

Ok so i had an extra spark plug unused laying around and i did a test. this is what happened:

First the bike started and rode fine. For about 10 min everything felt great. Then the bike warmed up and it bogged down but was still running(just at a much lower idle). So i pulled the left plug cap and the bike died. I started it back up and then pulled the right one and the bike stayed on at the lower idle speed with no change in idle speed. So obviously the right cylindar wasnt running.

So i placed a new spark plug on the left plug cap and held it to the cylindar and pushed the starter....i saw a spark
Then i did the same thing with the right plug cap .....i saw no spark.

I had an extra ignition coil laying around and replaced the right side. This took some time so the bike started up fine. After about 5 minutes it bogged down again.

I then put everything back how it was and tried switching the spark units and nothing changed, the right side was still down.

I tried switching the plug caps and wires, still no change.

CONCLUSION:
The problem must be electrical because the right cylinder is not sparking. The problem is not the Spark plugs, Plug caps, Ignition coils, the wiring harness, or spark units.


I am reading now into a possible faulty pulse generator or ignition advance, anybody have any experience with these and may know why one fails when bike warms up?
PS. the bike does use CDI

As it's only on one side I think we can count out the Advance and retard unit as that should affect both sides.Could be that the CDI unit is faulty and not supplying the right side correctly.The only way to eliminate that is to get or borrow a known good one and try it?

http://shop.ebay.com/?_from=R40&_trksid ... Categories

You don't want turbo or the,"Ignitor" types you want the CDI box like yours.Sometimes they are black/silver or gold but you know what they look like.They are a gamble but sometimes we have no choice and don't pay the silly high prices some sellers ask.If you have another CX owner close by see if you can swap one as a test?

There are some CDI tests in the manuals and,

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