I've got a 09 ULY XT, the problem is when the engines gets hot the check engine lamp comes on then it starts cutting the engine as if the kill switch was being Flickr off then on, the Rev counter and speedo go off and back on then check engine lamp on then goes off, the further I ride it the worse it gets to the point it starts back firing and become un rideable. Leave it cool and it'll be fine for a couple of miles then start again progressively getting worse.
I've only just bought the bike this week and the first time I rode it it did it after about 20 miles, the next time a couple of days later it went about 10 miles then today after about 2 miles so it's getting worse.
What I've covered so far,
Cleaned earths onto seat rails and across engine top stabiliser.
Dismantled kill switch cleaned terminals and tested
Cable tied ECU multi plugs to Ecu to eradicate vibration making bad connections
I've glad tested for fault codes and got one for temp sensor, when unplugged the resistance was fine, one for side stand tested and seems fine, and one for exhaust valve which appears to be working.

Any help would be appreciated.

Thanks Gary

So this sounds like a sensor, broken ECM (grey connector) or harness fault. Would be good to log some data and see what the signal is doing. Or borrow an ECM.

It's not vibration that affects grey connector, it is your weight on the seat pushing down on it. If you look at the base of the seat you will see where it has been pushing against the connector. There is a post that should be fitted to minimise this effect (which doesn't look as if it is on yours on the facebook photos - and there appears to be a screw missing).

What does the previous owner have to say about this?

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08 Specialized Langster

I just watched the video showing the tacho dropping to zero. So, the bits that could affect this are:

* Engine speed sensor
* Harness
* ECM (all the power for the sensors comes out of the grey connector)

You said the fault code was the engine temperature sensor.

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08 Specialized Langster

I haven't got the logbook back yet so don't know the previous owner, it was bought from a bike dealer but not local to me, I've got it booked in to a local place but not till next week, I'm just trying to get to the bottom of it before it goes in, they can then repair it and the bike dealers paying the bill.

While riding both the taco and speedo drop off, I think the check engine lamp comes on because it's lost power to the Ecu do when poweres restored the lamp would come on as normal.

I can replicate the fault by flicking the kill switch while riding

Good info, check the harness at the headstock

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08 Specialized Langster

......and swap the relays around

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Mithered ta death.
92 MB
96 S2T
98 S1W
00 M2
01 X1
03 P3
10 CR

I experienced a vaguely similar issue yesterday which I was just about to post about...

I have an '03 XB9S, and after 30 mins through baking London traffic and heat yesterday I stopped at Tesco. 5 mins later the bike started up perfectly and after 10 metres cut out. Then the fuel pump sounded odd, quite weak and slower when turning it on, but started, and then cuts out after about 2 seconds, as if hitting the kill switch. Tried a couple more times and the last time turning the throttle made no difference to the revs as if it wasn't attached. Then on the last attempt it backfired heavily so I gave up and picked the bike up in my pickup truck and hour later.

I started it again when I got home, even though the fuel pump still sounded odd, it started, and stayed on.

Then today the same thing, and after a couple of minutes the fuel pump also went back to sounding normal.

Just the heat? All the fuses are fine though.

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Life moves pretty fast. If you don't stop and look around once in a while, you could miss it.

Got stuck in Macclesfield today for 15 mins or so..Stopped in pull in and wouldnt start..No prime..Engine turning but no starty...Incidently, i couldnt find the shop i was looking for so the whole journey was a complete waste of time, and got lost on way back,, im starting to quite like getting lost..Anyway, eventually it primed and started, so made my way home ish...Phoned Maz who told me to swap relays diagonally ..so, when i turned key and no starty i pulled bottom right relay out, as i wiggled it out it primed... ..I swapped all 4 relays and as i write all is fine..Hope its sorted..I do have the block to stop grey connector gettin squashed but looking at seat there is contact with black connector but only a bit....This prob also happened on way back from the Maz bbq.

A special thanks to Maz and Adam for there kind support through these difficult times...

No need to thank me, I just offered a trailer to take it to Maz

Glad it's sorted though

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If your dreams don't scare you, they are not big enough.

Back to the broken grey ECM connectors, I think we need a masterclass cos someone has just sent me one that has obviously been in contact with the seat. Before that was dieseldoc, then before that willybuell, the list goes on... I'm not sure if you guys think that ECMs grow on trees but there is now a shortage of anything of any use...

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08 Specialized Langster

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Mithered ta death.
92 MB
96 S2T
98 S1W
00 M2
01 X1
03 P3
10 CR

Is the grey connector issue specific to Uly's and if so all years and models?

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To Lands End and beyond

I have the block on mine but also cut a hole in the seat base to give more clearance ,
Was up at friends the other day who’s got an old but very clean Suzuki 1300 , and ecu is playing up, fuel pump intermittent priming and ignition advance kicking back on the starter , cost of new ecu form Stealer ship £1500

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Buell Ulysses XB12X 06/08

Big problem on 08/09/10
Less of a problem on 07 but still happens (connector is not as high)
Even less of a problem on 06 (seat sponge is thicker)

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08 Specialized Langster

..but you can still get them, the Buell supply as Pash & Maz say is drying up

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Feros Ferio