Intermitten Spark

[mellco]

Hello all,

I'm back to partake from the "Fountain of Knowledge". My 1996 Royal Star developed a "miss" and would backfire. In doing some checking I found that I have an intermitten spark from cylinder #3. This condition exists when the bike is cold or warm that in my thinking would rule out the coils because from what I have read the coils fail mostly when they get hot. Any suggestions?

[buddy]

Do not know about the 96 model, but on my 83 it was the pigtail for the pickup coils - getting bad connections. Unplugged the pigtail cleaned the connections applied electric grease. the rest was history no more problems....

[frogmaster]

Hello all,

I'm back to partake from the "Fountain of Knowledge". My 1996 Royal Star developed a "miss" and would backfire. In doing some checking I found that I have an intermitten spark from cylinder #3. This condition exists when the bike is cold or warm that in my thinking would rule out the coils because from what I have read the coils fail mostly when they get hot. Any suggestions?

 

I have had a single "intermittent" Spark Plug.... swap with another spark plug from other working cylinder to see if problem moves??? If problem moves... replace spark plug.

[dug050]

I would like to bump this post for some further discussion. Mellco, were you able to resolve this problem?

I also have a 96 RS with a similar problem on cylinder #3. I am getting some backfiring on this cylinder on cold start up and the pipe does not warm up until it has run for several minutes. I hooked up my inductive timing light to this plug wire and it showed that it was not firing. I removed the plug cap and cleaned the corrosion, I also cleaned the spade connectors on the coil and installed a new sparkplug.

This morning I did another cold start with the timing light connected and now have spark and the pipe heated up like the others but when I rev the engine the spark still becomes intermittent above 3000 rpm. I hooked the timing light up to cylinder #2 plug wire and get constant spark through full rpm's.

Can anyone tell me if the TCI fires all 4 coils from one output, I assumed that the TCI was OK if the other plugs are firing properly, right or wrong?

I plan on checking all the connectors and plugs from the coils back to the TCI since it seems like a bad connection could cause this, am I on the right track?

Can a coil fail at certain RPM's and work OK at others?

If cleaning all the connections doesn't solve the problem I will probably swap two coils and see if the problem moves.

Any comments would be appreciated.

 

Doug