1200 GSA Throttle Problem

[pedro]

Gents your assistance please-

About 6 weeks ago, I was travelling on a stretch of motorway, 6th gear, 75mph, when the bike suddenly lost power. Revs dropped and power delivery became jerky. I pulled off the motorway and the bike was running rough, sounded like the silencer baffles had been removed. I had the bike recovered to the local dealer, who diagnosed it as a sticking throttle switch, which was apparently sorted without having to replace anything.
Last weekend, I was on a run back from Fort William when I encountered a similar problem twice within the space of 50 miles or so, same speed, 5th gear at an even speed, revs dropped, blipping the throttle didn't help, then suddenly it clears and I get a surge of power. Throughout the remainder of the trip I was scared to overtake in case this happened again mid manouvre. The bike goes in for a 12k tomorrow and I'd like to bottom this problem out. So, throttle switch or something more sinister ? There were no warning lights displayed, well I don't think so, I was busy shitting myself.

 

[Big Nick]

Could possibly be the Fuel Pump Controller on its way out?

That seems to be the most common cause of these sort of problems see if your dealer will have a look at it

 

[st247]

It does sound like the throttle position sensor, there's been a few posts about them on here. Not as common as the FPC.

Not really sure how they managed to cure the sticking switch without replacing it

 

[RickG]

If the bike was running all the time, even if very roughly, it does seem less likely it's the FPC as normally these just die and you are left with no fuel pressure and the engine stops dead. The throttle position sensor can't 'stick' as far as I'm aware since you are pulling on it with the throttle cable? A failing TPS could seriously mess up the air:fuel ratio and cause all sorts of misfire. Have you accidentally clobbered the connector on the LHS throttle body as it's quite vunerable to big knees?

 

[pedro]

No,

having split the throttle switch in half on the last bike during a slow speed spill, I now have a touratech guard fitted, which copes with the knocks etc. I now have the bike back from the dealer and they are reporting 'no fault'.
Certainly a strange one, I've just hammered the bike down the bypass and I'm also unable to replicate the fault.
Thanks for the advice though folks.