Coil going under load

[AndyB]

Alright fellas,
Has anyone had an issue with our coils breaking down under load..
Bike was on the dyno but has developed a misfire around 8000+
Running up to 8k it's fine....I would like to rule out the coil before I start pulling it all to bits AGAIN ..oddly enough only number 1 plug was slightly oily compared to the other 3....

[Eric GSX1400K3]

Can't say the needle on my tachometer has ever seen 8000rpm.....

[GSXKING]

  ask @Notty that question 

[Notty]

Can't say the needle on my tachometer has ever seen 8000rpm.....

I didn't know it went that high !! 

[grog]

Never been 8k either.

[Hooli]

I'd pull the plug caps off & check the end of the HT lead is good, probably trim 5mm off while you're there to ensure it goes back right.

I'd expect two plugs to drop with a coil issue, from memory plugs 1 & 3 run off the same coil.

[AndyB]

I'd pull the plug caps off & check the end of the HT lead is good, probably trim 5mm off while you're there to ensure it goes back right.

I'd expect two plugs to drop with a coil issue, from memory plugs 1 & 3 run off the same coil.

Yeah..as I say,
It's a bit weird only number 1 plug is slightly oily....you would expect 2 plugs to be off...I've bought a set off Ebay to swap out.just to prove the coils, I had this issue when I was younger on a z1000 and turned out to be the coil going under load.. never seen it up until then..
Spent a fortune on new electronics for the bottom set of injectors and getting them wired in etc....they run off signal wires..so if they fire low down the rev range..they will fire higher up...
I.ll prove the coils 1st......and work back from there...

[Hooli]

Could be a dodgy plug too.

[AndyB]

Could be a dodgy plug too.

That was the 1st thing I changed mate...infact done it twice.once with a new set...and again with a proven old set....
I was just interested to find out if coils going under load was a ....well not common....but had happened to someone on the forum before...I,ll get to the bottom of it...its probably the bottom row of injectors that are fuggin up....I'm sick off taking this fuggin thing apart

[grog]

Andy, i have a coil tester machine, must be someone near you with similar. It tests modules and coils. Just hook up a good module, usually old skool flat Bosch, HEI plug tester, and coil. It just runs coil thru test, not sure but think it goes to simulated 10 th revs. Would need two High Energy plug testers for 14 coils.