Intermittent spark

Shajota

Shajota

Hero member
Location
Whitsundays Qld
The AE started on the button this morning then conked out. Started up again but would only run on 1 cylinder with other one cutting in intermittently. Thought it might clear so took off but other cylinder would only cut in every now and then.
Turned around and took the orange one out so left it to sulk for the day in the garage....:)
Had a quick look late this arvo and grounding removed plug shows a definate intermittent spark. Sometimes would spark for a bit then stop all together. Other times just cut in spasmodically or very weak. Changed plug caps over and still persists on the same side and changing plugs made no difference.
Didn't have a chance to go much further but I presume it is either a condenser or Coil issue (or bad connection I suppose)?
The sudden failure seemed weird and didn't quite seem like a condenser problem but I am probably wrong. I will put in spare set of points in next few days to check but thought I'd ask for considered opinions here.
I haven't had a chance to check all connections (earths) and I understand these coils are usually reliable but I am betting on a bad coil.
I haven't searched here yet but is there an easy check for a coil?
Welcome thoughts.
 
As you say, coils are not a known weak point. Difficult to test under operating conditions - checking for primary and secondary resistance is about it apart from substitution. Condensers will and do fail with age. I'd focus on that, as well as wiring for poor/broken connections/terminations.
 
Just swap connectors to the coils and if the problem travels to the other side, the coil is your culprit. Might have to rig up wire extensions to get from one coil to the other - or just pull out the coils and swap their possies - doesn't have to be shifted back regardless of whether one needs replacing or not.
 
The battery cables on my 750 were badly corroded, so consider replacing those, along with the starter, spark plug and coil wires- also the small inner connectors on the coils
 
Ok, thanks for replies. Still thought it weird the way it happened so 1st thing this morning had another quick look in the sober light of day.
Checked the points and noticed wire to LH points was sitting out a bit, only partially in.
Pushed the wire all the way home and hit the starter. Sparking as per normal, so looks like just a dodgy connection. Put plugs back in, tank on and started up, purring beautifully. Will take it for a ride later to ensure no fail when components warm up but was still cold at initial failure.
Sorry to waste time with such a non event.
( I did check my records and plugs were last changed 27,000kms (17,000mi) ago so as a special treat might just leave the new plugs in that I used for initial check:p)
 
You must log in or register to reply here.
Back
Top