Bike Cutting out!

[squibb34]

You have explored most of the avenues mentioned, but I'm still wondering whether it is the ECU/ICM heat sink issue, which doesn't show itself unless/until the module overheats - 32 years old, hot weather &/or a very hot airhead engine.

This is the theory. Beneath the tank, the Ignition Control Module is fixed to a mounting bracket that acts as a heat sink, with a bond of thermal conducting paste, aka heat sink compound, as the filling in the sandwich. With age & heat cycles, the paste fails, crumbles away, leaving a minute air gap, which the allows the module to overheat, typically cutting the spark completely, shutting down the bike suddenly whilst riding. Once the module cools down, maybe after only 5-10 minutes, the bike can then be restarted, sometimes with a hefty backfire due to unburnt fuel that has collected in the exhaust.

It has to be worth a look for peace of mind. This is some top end thermal paste from the IT world - others are readily available.

https://www.ebay.co.uk/sch/i.html?_nkw=ID-COOLING+FROST+X55+Thermal+Paste&_sacat=0&_from=R40&_trksid=m570.l1313

 

[tofgasp]

My first thoughts where the right hand switch, and a cracked coil, but you say it's ok, and also checked the connectors, so... There has been some reports in the US of strange Wedgetail behaviour... If you still have your original ignition, I would try to go back to it.

 

[Gelandestrasse]

The only thing that would stop the starter working is lack of 12V at the starter. A thing that could cut the engine whilst running is lack of 12V at the coil (or other ignition parts). The common 12V supply to these is via the ignition switch. The green wire supplies the ignition system and the start button (latter via the green/yellow wire). The red wire to the ignition switch supplies the green when the ignition switch is in the correct position. Check up behind the headlight and remove the ignition switch for inspection (you mentioned bare cables up there?? ) . I've had a fire there before, so check all cable routings for shorts. You don't want to have a fire.

 

[Gaston Skydrol]

The only thing that would stop the starter working is lack of 12V at the starter. A thing that could cut the engine whilst running is lack of 12V at the coil (or other ignition parts). The common 12V supply to these is via the ignition switch. The green wire supplies the ignition system and the start button (latter via the green/yellow wire). The red wire to the ignition switch supplies the green when the ignition switch is in the correct position. Check up behind the headlight and remove the ignition switch for inspection (you mentioned bare cables up there?? ) . I've had a fire there before, so check all cable routings for shorts. You don't want to have a fire.

Cheers! I took the ignition switch out yesterday as part of my search. I’ll let you know how it goes. I did have issues there a while ago.

 

[Gaston Skydrol]

Cheers! I took the ignition switch out yesterday as part of my search. I’ll let you know how it goes. I did have issues there a while ago.

I’ve removed all the cable protection from the loom down from the ignition switch to the main loom. Nothing found so far. There are signs of different tapes on the loom but not unusual for a bike of this age. I’ve owner her for 20 odd years and I’ve never gone this far before. Wondering if it’s a duff ignition switch. The actual lock is obviously well worn. Wondering if there’s something inside. Unable to reproduce any symptoms when it’s running.

 

[Gelandestrasse]

I've had experience where the two parts of the ignition switch try to force each other apart, causing the connections inside to part company (and hence.... ). I can't quite remember the details but I think the back tends to fall off. I can't remember how I fixed it either, but all will come apparent when you squeeze the switch axially and it moves. I'll try and take some pictures later as I think I kept the old parts.

 

[Gaston Skydrol]

I've had experience where the two parts of the ignition switch try to force each other apart, causing the connections inside to part company (and hence.... ). I can't quite remember the details but I think the back tends to fall off. I can't remember how I fixed it either, but all will come apparent when you squeeze the switch axially and it moves. I'll try and take some pictures later as I think I kept the old parts.

I have stopped looking on the loom under tank. I’ve gone from the handlebar switch (rh) and the ignition switch and found nothing. I have found that I can’t full turn off the lights. The switch is stuck on sidelights. Never noticed it before as I always ride with the lights on anyway. Ignition switch is the original I can’t get the bike to stop by moving the key or the kill switch. I thought I was onto something when it would not turn over with the bike in gear and the clutch pulled in but when riding the clutch switch and the neutral switch are out of the running. The ignition is best described as very wobbly but obviously can’t see how the contacts are at the base. Going to take the right hand switch to bits tomorrow to see if I can get the lights to fully turn off again. Had to stop work to fix the car as it failed its French MOT. Inspected everything under the fairing but it’s not long ago I was in there so didn’t find anything.

 

[Gaston Skydrol]

Spent best part of two days buggering around with the electrics. Found nothing! The r/h switch was shitty tbh so had it to bits cleaned all the contacts out and even the light switch works now so at least I’ve achieved something. Using a remote fuel tank I’ve been able to run it and have a good fiddle with the cables and switches. Bike runs flawlessly! Getting hung up on the ignition switch play but mucking around with the key while the bikes running reveals nothing. Just going to put it all back together and carry on. At least all the connections are clean and the loom tidy! Not sure if it’s good or bad news?

 

[Gaston Skydrol]

Current sit-rep. Put the bike back together. First turn of the key, normal warning lights (oil,neutral etc) hit the starter…….nothing. Turned the key off and on again everything worked. So took the ignition switch off and prised the switch off the lock took it all to bits. Found lots of shit in the actual contacts and the springs in the mech very compressed. Gave them a little stretch, cleaned everything and put it all together again. No more play in the key mech, cleaned that all up as well. Once all back in the bike it’s like new again and after a long test ride in the rain, no more issues. At some stage I will have to replace the switch as some of the contacts in the base plate looked a bit sad, but for now all is well. Thanks for all the help and ideas. I still don’t get why I would have the warning lights but no power to the button but for now I’ll take it as a win.