Is It The Coils?

How old is the fuel? The most volatile fractions will have evaporated off over winter making for harder starting and slightly reluctant running.

Any obvious misfire?

 

Let it run for 12 mins, or untill the fan kicks in, after starting, without touching the throttle. That resets ECU

 

Failing ECU reset it sounds suspiciously like the symptoms I had with a Gill coil on its way out on my Bonnie. Since you have three coils the trick is to buy one replacement and identify the culprit by substitution. PVL 1290007 is the one you want.

 

Cutting out when hot and re-starting only after cooling down for a while are classic symptoms of a failing crank position sensor, which is not unknown. But I've not heard of it affecting cold starting so other causes should be considered, as per the above suggestions.

 

Absolutely. Only affects your carburation. Both the coil and crank sensor are coils with very fine copper windings. Over time they are prone to break but often go intermittent before total failure. The coils proper provide each cylinder with their spark while the sensor sends a pulse to the ECU to trigger each spark at the appropriate point of rotation.

 

I should have said from cold.

 

Give it a goodly slug of Redex or similar which will clean out the fuel system especially the carbs which may have a bit of muck in them. My Trident was hesitant on its first ride out after winter lay-up a few years ago. A dose of Redex cleared it within a very few miles. Can't do any harm!

 

You might think so but they can stutter inconsistently before dying for good. Got a multimeter? If you unplug the crank sensor lead under the side cover/adjacent the battery/air box you should get just under 600 ohms resistance from one side to the other. If you cannot locate the connector dress making pins through each lead will get you in. Tape up holes afterwards. Likewise each coil should measure something like 18k ohms from plug lead socket to the grounding earth where it mounts to the frame.

A ‘1’ (infinity) is open circuit and your culprit but sometimes only substitution provides definite proof. The crank sensor is the easiest place to start. It certainly sounds like a coil acting up as it gets warm.

 

No. That is a big, fat, wagging finger pointing at the pickup coil.

 

https://www.triumphparts.gbr.cc/product.php/2927154/

Right model?

 

Only for efi bikes. A TBS only has an igniter not an ECU and does not do adaption