K1300Gt exhaust can glowing red

[nookles]

Hi all
I have a 2010 K1300GT which is running on 3 cylinders until around 2000 rpm then seems to run fine after that.
I have a seven mile run into work, and the bike must be burning fuel in the can as it is glowing red hot internally by the time I get there. Header pipes are fine and a fairly even temperature across the four.
I have had a BMW mechanic run a 20k full service and diagnostics with no fault codes, but he has been unable to source the problem
All injectors checked for resistance.
Throttle butterflies checked.
All spark plugs renewed.
No 2 cylinder plug cap was swapped for one of the others and then the adaptation values were reset.
Fitted booster plug which registers the air temp correctly and is doing its job enriching the mixture.
At a complete loss what to do next so any suggestion will be welcome.

[TomL]

When iit's running on three cylinders, take the temperature of each headerpipe as it exits the cylinder head, with an infra red thermometer. This will show which cylinder is not firing. I'm guessing that you have a faulty coil.

[raesewell]

What he said

[Phmode]

Well, he does say the header temps have been checked and are fairly even across the four...so was that by a thermometer or by spitting on them and listening to the sizzle?

[nookles]

Yep, used a thermal image sensor. Don't know for sure but i suspect the mech will have disconnected each coil in turn to determine that its No 2 cylinder.

[Phmode]

Coils are a known failure on the K, either low down and fine at revs or vice-versa. Either way, you need to change all four despite the cost because the cost of labour to get to them is worse than the cost of the coils. After market coils are available which are more affordable than the OEM ones and just as reliable from reports.

Also, why you have a booster plug fitted is a mystery, richening the mixture is asking for trouble with your current fault and does very little for the performance of the engine anyway.

[nookles]

The mechanic didn't think we needed to replace all four coils.
The coil caps were swapped between the new coil on No 2 and an adjacent coil.
The problem was still with No 2 which has me thinking its a wiring issue.

[Gingerchunkyboy]

I had a glowing red/orange end can on my K1300s with rough low end running i took my plugs and coils out the plugs were a normal colour . i convinced myself i had an air problem so i loaded the parts cannon with a secondary air valve an idle actuator and a lambda sensor . I fitted all 3 parts and the problem cleared up i cant say what fixed it but my guess would be the lambda sensor. Im no expert just passing on my experience .

[raesewell]

That's always the trouble with loading up the parts cannon, you never know what was wrong.

[Phmode]

The problem with the bits on the airbox is that it is a pain to get to (particularly for the mechanically challenged among us) so changing both parts at once is the easy way out. The total cost of the bits isn't exactly crippling so the scatter gun approach is reasonable.

[raesewell]

I understand the parts verses labour, however if you want to know what the problem was you need to change one part at a time.

[Phmode]

Only if you want to know, most folks want a cheap'ish and effective fix, especially if the bike is your commuter.

Back in the early days of the sticking throttles, when I had the airbox off and on the K12 more times than I could count, I never found what was causing the problem but a cheap (£99) set of throttle bodies of a newer bike fixed it.

Being an anal type I phaffed around with the duff ones for weeks trying to find what was causing it, all to no avail. Most folks would be happy with the fix and bin the old ones.

[raesewell]

I know Brian, but you know what I'm like. 

[Phmode]

 

[black-k1]

A few years ago we did an Old Gits trip to the French Alps. The chap on the K1200S had saved money by only replacing one coil. Sure enough, on about day 2 or 3, his 1200/4 became a 900/3. That was his holiday ruined!

If it were me, I'd replace all 4.