1150 running rough

[kwallace21]

Tricky one this. My 1150GSA 04 Twinspark has an intermittent running fault.
Sometimes when it gets to 4000rpm it starts to get very vibey and feels quite rough. Now I know it's a big boxer engine and they all do that but other times when I'm out it is much smoother. It's the random nature of the fault that is confusing. The bike has 12k on the clock and has had the TB's balanced, valves checked and before anyone asks, I have replaced both stick coils. I will replace the spark plugs tonight but dont expect that to cure it. Oh, do you have to gap those funny twin electrode plugs out of the box or can I pop them straight in?
Cant work out why the roughness is intermittent.
Any ideas.

Help me Obi Wan, er I mean Steptoe, You're my only hope!

ta
Kev

 

[kwallace21]

Aha! I knew this would stump you lot!
Will check the throttle cable seating but it is unlikely.

kev

 

[MattW]

I'd guess it's the 'I've changed both stick coils' bit that's stumped people.

I take it you balanced the TB's on the cable adjuster at higher rpm as well as at idle on the air screws?

If it's not TB's or cable seating then I guess it must be an ignition issue but that'll need someone clever who knows about twinsparks to chip in.

 

[sparkplug]

Hall sensors?

 

[kwallace21]

Had a wee look on that American " Adventurer" website and a few guys have mentioned symptons exactly like mine on both 1150 and 1200's. One day runs smooth, the next day runs rough. Dont get me wrong, it's not unrideable but it is a little frustrating. One North American fellow said if he did the tps opening and closing throttle switching off then back on thing, the the occurences of running rough were greatly reduced. maybe my bike is haunted.

 

[Steptoe]

. One North American fellow said if he did the tps opening and closing throttle switching off then back on thing, the the occurences of running rough were greatly reduced.

I'm always amused when this remedy is suggested. But because it's written in a manual people assume it's some sort of magic function.

Your doing the same function every time you ride the bike.

Even when pulling the fuse or disconnecting the battery when the throttle range is wiped from the motronic memory, just by riding the bike for a couple of miles reprogrammes the throttle range - By pulling the motronic fuse then replacing it, turning on the ignition and opening the throttle fully twice then turning the ignition off, then on and restarting is only doing the same thing as riding it for a couple of miles.

 

[Steptoe]

Aha! I knew this would stump you lot!

Not stumped, but not enough info for diagnosing.
Going by what you've written it will all be guesswork which may cause other problems and suggesting things to check when it's an intermittent problem isn't going to help.

Good luck .

 

[kwallace21]

Thanks for getting back to me Steptoe. i figured the bike does its own TPS thingy on start up anyway. Will change the plugs in the off chance it's a fault with a secondry maybe. Do you gap them? Manual says .8mm but they look kinda right straight from the box.
It is a tricky one to diagnose over the phone so to speak. I was hoping it was something dead obvious. Life is never that simple.
Will let you know if I get to the bottom of it.

cheers
Kev

 

[CHANGELING]

When was the last time you changed the fuel filter...believe me if all the other variables are within specification....try this as it may be a clogged filter.

 

[Packer]

When was the last time you changed the fuel filter...believe me if all the other variables are within specification....try this as it may be a clogged filter.

I'd have thought that unlikely with only 12,000 on the clock.

 

[mandon]

03 1150 gs.....twin spark with 29k+ kms on the odo....
few days ago, the big started to run rough.....it seems that its misfiring...my initial guess was, somehow water have gotten through in the tank....then it was hard to start...it took about six tries to start it....and when it starts it feels like its going to die...and the idle was very rough.....so i tried valve clearance, end float clearance, tb synchro...to no avail.....
today the mistery was solved...it was a ruptured fuel line inside the tank....after it was replaced the thing run smoothly agiain....

 

[roddy]

Kev, just as an idea, and a simple check.

what are the condition of the o-rings on the BB idle screws, if there a bit iffy you may get air leaking past them, which might be upsetting the mix ? a long shot but it'll cost nowt to fix

 

[kwallace21]

Thanks Roddy. Will give that a look.

cheers
Kev

 

[boudenoodty]

Hi,

Got the same problem which was lasting for a couple of weeks. Tried everything from syncing, cleaning air filter, injector cleaning fluid in the fuel, ...

It finally turned out to be one of the coils which are inside the cylinderhead.

You can easily check whether or not these are still OK:
While the motor is running, disconnect the small connector located on top of this coil, if you hear a difference in the running of the motor, the one disconnected is still OK.
If you don't hear a difference in the running of the motor, get you another cylinderhead coil. .... Will cost +/- 100EUR though,

Seems to be a common problem on late 1150's and also on the 1200 CC motors.

HTH, Yvo

 

[Steptoe]

You can easily check whether or not these are still OK:
While the motor is running, disconnect the small connector located on top of this coil, if you hear a difference in the running of the motor, the one disconnected is still OK.

Better to pull the bottom secondary plug caps for a more definate test

No listening for sounds, the engine runs or not

 

[boudenoodty]

removing the bottom one is quite difficult on a GSA with the cylinder guards and fall-bars fitted without having to strip it all off ;-)

But you can definitely hear the motor starting to run much/less smoother after disconnecting one side without being an expert :-D (Which I'm not)