Replacement HT leads

I've been adding a few bits to my 2011 Roadster over the years an it's about how I want it, so I was a bit pissed when it started an with intermittent misfire a couple of months ago.
The engine revs freely to 7000rpm through all gears and has been professionally tuned on the dyno to extract the benefits from a few mods.
The problem appears after operating temp has been reached and around constant speed 2000 revs, it's best described as if one cylinder is lagging the other two for a second every now and then.
I checked the plugs and replaced them after finding cyl 1 plugs black compared to brown for 2 & 3.
Resistance is within tolerance across the 3 coils however I found that one of the coil 1 HT leads has gone open circuit.
It appears that Triumph don't sell individual HT leads and want $368 Aus for a full set, so I'm up for a sh$t load of cash to find out if this is the problem.

Has anyone found a cheaper replacement for a single HT lead ?

My other option is to buy a used coil and swap the leads but prefer new if it can get it.

Look at COP conversion, R1 coils sticks, there's a member who does loom for it, definitely cheaper and better

I have just done this with Chinese copy coils. Yamaha coils were $200 each for 4 used coils..So just over $100 delivered for 8 coils about $20 delivered for the coil plug connectors, $5 for 2 pin waterproof connectors so I could bin the blade connectors. coils tested at between 1.4 to .8 ohm each, depending on which multimeter and what music was on the radio.. (buggered if I know why they read different). Wired in parallel the pairs all tested between 1 and .8 ohm.. Wired in series tested at 1.4.. Connected up today and ran fine, bit of a hiccup occasionally, Then found a vacuum line disconnected, and air temp? sensor in the air filter unplugged.. Got 8 minutes into a 12 minute reset and it started pumping coolant from the overflow on the A/M catch can so said fuggit and packed up till tomorrow..

Fitted COP set, replaced vacuum hoses, cleaned crank sensor, checked MAP sensor, cleaned air box sensor, cleaned and used dielectric grease on all connections, replaced fuel filter previously, syncronised TB's, replaced TPS, disconnected stepper motor. no error codes. pulls like a 16 yr old when accelerating.
After travelling 10km from a cold start the hesitation starts at constant throttle, 1800rpm. (ambient temp 23deg C)

What can it be ?? - wiring loom ? - ECU ?

Pete said:

Fitted COP set, replaced vacuum hoses, cleaned crank sensor, checked MAP sensor, cleaned air box sensor, cleaned and used dielectric grease on all connections, replaced fuel filter previously, syncronised TB's, replaced TPS, disconnected stepper motor. no error codes. pulls like a 16 yr old when accelerating.
After travelling 10km from a cold start the hesitation starts at constant throttle, 1800rpm. (ambient temp 23deg C)

What can it be ?? - wiring loom ? - ECU ?

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Probably fueling/timing in the map at that 1800 spot, probably not perfect at 2k or you’d probably just add some throttle, i would guess its a tuning issue in that range, which is a pretty important range. 1800 to 2200 i find myself in alot. Good luck with it.

Kevin frazier said:

Probably fueling/timing in the map at that 1800 spot, probably not perfect at 2k or you’d probably just add some throttle, i would guess its a tuning issue in that range, which is a pretty important range. 1800 to 2200 i find myself in alot. Good luck with it.

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recent dyno tune resulted in good smooth power on acceleration