Running rough, won't idle, loud thumping

rup5555555

Registered user
Joined
Aug 13, 2005
Messages
146
Reaction score
0
Location
England
Hi all

I was riding to the channel tunnel yesterday and on the motorway my R12GS lost power and the exhaust note changed, sounded like a thumper on the throttle. When I stopped it would not idle and just stalled. I restarted it and limped home having to keep the revs up when stopped else it would die on me, all the time under powered sounding like a thumper.

Any ideas? Thx
 
Are both cylinders firing? Could be the coils maybe

Were there any other symptoms prior?
 
no other symtoms prior, just started on the motorway. How would I test the firing? Thx
 
A mate had the same symptoms occur, turned out to be a damaged RH piston requiring a strip and rebuild under warranty.:eek:

I had a problem once with my bike only running on 1 cyl and failing to idle. Left it for the day and it bizarrely fixed itself after a TPS reset.

Not trying to put the fear into you, lets hope it's something basic.

Simple things to check:

Both throttle cables seated correctly in the throttle bodies?
Throttle cable routing checked from handlebars to splitter beneath thank to throttle butterflies?
All cabling intact?
Tried the Throttle Position Sensor reset routine?
Spark plugs tight?
Battery fully charged?

Know anyone with a GS911 device that could do a diagnostic check for you?
 
Use a drop of water, don't use your hands those pipes get super hot super quick.
 
Rupert, it is either spark, fuel or compression. You need all 3 to make the engine work. Engine valve and spark timing is fixed so no worries about that.

Spark: Check the wiring to the mini coils, try a TPS reset after disconnecting/reconnecting the battery (may reset the fuel and ignition computer). Be sure the battery is fully charged too.

Fuel: Check the cabling for the throttles, if one cable has slipped the bike will get less fuel to the affected side. If the bike runs on 1 cylinder, the fuel pump is running and fuel is in the tank. Check the wiring to the fuel injectors, they should be tightly clipped in place with a rubber gaiter over them.

Compression: Are the spark plugs tight? If one is loose you could lose compression. If the engine has any mechanical damage to piston/valves (lets hope not) this would also affect running but thats beyond easy repair.

Work methodically around the bike and hopefully you'll sort it.
 
just checked the temp on the heads and exhausts and they are both getting hot, same temp (hot) after 45 seconds of thumping away... it even misfired on first start after laying up for a few days. I will start a full check on Thursday but in the meantime any other ideas on where to start? Thx
 
Rupertexists said:
Hi all

I was riding to the channel tunnel yesterday and on the motorway my R12GS lost power and the exhaust note changed, sounded like a thumper on the throttle. When I stopped it would not idle and just stalled. I restarted it and limped home having to keep the revs up when stopped else it would die on me, all the time under powered sounding like a thumper.

Any ideas? Thx
Click to expand...

Throttle Position Sensor almost certainly.
 
No, but you can reset it as follows:.

Disconnect the battery for 30 seconds then reconnect.
Turn on ignition but DO NOT start the engine.
Roll the throttle shut-fully open-shut three times.
Turn off ignition

This will allow the ECU to 'relearn' the full range of travel of the throttle.

Turn on ignition and restart engine. It should hopefully now run properly again.
 
do you think this problem has has anything to do with me installing an new Odyssey battery 2 weeks ago?
 
Rupertexists said:
do you think this problem has has anything to do with me installing an new Odyssey battery 2 weeks ago?
Click to expand...

I think it unlikely, esp as it appears from your post the bike has been ok since new batt fitted.

My TPS went awol in France with exactly those symptons
 
I had the same problem with my bike last year, went to use the bike for the first time in a month (after sick leave), started the bike and it ran as you describe.

I took the car to work, when I got home I did the TPS reset routine and the bike has been fine since.

Can't explain the reasons for it, other than maybe the bikes ECU having "electronic flu".:nenau
 
Rupertexists said:
do you think this problem has has anything to do with me installing an new Odyssey battery 2 weeks ago?
Click to expand...

Yes. To do a TPS the battery must be disconnected, then reconnected; it follows then that if the battery is disconnected then reconnected a TPS needs to be done.
If you do not want to disocnnect tbe battery again, simply try turning the ignition on, let the checks finish, then open the thriottle fully, close it fully, repeat two more times. Turn the ignition off, then back on again. With the symptoms you have described as soon as you start the engine you will know if it has had any impact.

If it does not, then disconnect the battery for 30 seconds, reconnect and try again.

Hopefully, that should have you back on the road in seconds....
 
i had the battery disconnected for about 6 hours on sun and bike ran perfectly normal afterwards.

i hope that a simple TPS reset get the OP back on the road.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
You must log in or register to reply here.

Similar threads

Twin spark won't idle and rough running
Replies
11
Views
1,197
Purplegerbil
Wizards-Online
Running rough... Help and suggestions gratefully received
2
Replies
23
Views
6,982
Wizards-Online
Wizards-Online
pistolpete
Running rough when cold
2 3
Replies
48
Views
8,797
bikemad
bikemad
Won't idle and seems to be running on one cylinder
Replies
10
Views
2,122
davegs
davegs


Back
Top Bottom