techie help required please...

[RichieToye]

I have a 2006 1200g, the only non factory thing is the K&N air filter, the bike has been in the garage for 4 months and when i went out on it yesterday the following happened...

bike started fine and would happily rev away once warm.
once i started riding it, if i opened the throttle quickly the bike started coughing and spluttering, if however i opened the throttle just an inch then the bike would happily behave. if i pulled the clutch in when moving the bike would also rev away!

so its just after an inch of throttle movement then it becomes a dog back firing and coughing and spluttering and juddering away...

any ideas please and TY.

 

[Timpo]

I'd try a few gallon of fresh petrol..... higher octane stuff too.
Doesn't sound a very technical reply, but first thing I do when any of my bikes have been laid-up is new juice.

 

[skywalker]

Has the battery's been disconnected ? Did you fully twist the throttle 3 times with igntion on for the first time?
Make sure the TPS on the left throttle body plug connection's not been knocked of and also check the ignition coil connectors under the covers for correct connection - they can dislodge and seperate from the coils.
Try 4 new plugs - ie repeated starting with the bike not going any where can flood the plugs.

 

[solidstate100]

Yep TPS reset and fresh fuel see how you go

 

[bikerider007]

I have a very similar problem at the moment with my gsa, i have dumped the fuel new tank of fresh still the problem exists tried, new plugs as well cleaned the air filter i am running out options thinking it might be a the fuel pump controller thingy now starting to go wrong???

 

[Stimpytim]

What colour are the exhaust fumes once it is warmed up? If sooty, then maybe a fuelling issue, with a faulty sensor somewhere?

I had a similar problem this year, with the motor running rich due to a combination of a throttle position sensor fault and oxygen sensor problem.

 

[bikerider007]

no soot, here nice grey pipe standard pipe as well is it possible
to rest the tps?

 

[aspiring]

does the gs have a fast idle mechanism (like an old style choke) if so the cable might need oiling as its not releasing fully when dis-engaged

 

[Deleted account 190920001]

Old fuel is possible but unlikely. I have a bike that the fuel is 10 years old and it starts and runs fine once a year. Could be a coil or plugs, pull the plugs and have a look.

 

[bikerider007]

if i open the throttle quickly it judders and shakes but if i open slowly it's Ok ish and dosent judder

 

[alex_rsa]

Most likely a coil has broken down.

I have written a "how to" giude in a previous reply so a bit of searching should find it. It costs nothing to check them and the symptons sound the same.


Found my original giude:

Sounds like a coil. i had one fail, it started under load but got progressively worse over a week or 2.

Biggest problem was working out which coil, tried all sorts of combinations and would ride up the road only for it to appear/dissapear. Also tried a new plug.

In the end I disconnected all the coils except one and started the bike. It will start quite happily on 1 working plug (don't ride it anywhere), after going through 3 of the plug/coil combinations the bike would not start - this is the dud coil.

Just to double check try the same spark plug with another coil and it should start.

Sounds fiddly but it takes 2 minutes.

 

[bikerider007]

what is/are a coil/s? where are they located? i have fixed lots of things...... on a gs but not run into these before my gs is a 06gsa btw
cheers

 

[RichieToye]

Thank you all...

The plugs look ok, i have reset the TPS, i think ill now try the coils as it seems they might be the issue and their not coping with the load as the throttle increases - any more thoughts?

 

[ghiribizzo]

Coil(s) are what makes the high voltage that sparks the plug to ignite the fuel.
Older cars and bikes eg airhead, oil head have a central coil(s) with HT leads out to the spark plugs.
later ones have thin 12v carrying wires out to the spark plug with a stick-coil mounted directly on to the plug.

Before buying new coil(s) in a panic, change the spark plugs.
Ducati 600/750/900 SS-Monsters were favourites for crappy starting and running and miracle cures with new plugs. If it's been sitting a long time, it's a possibility that the plugs are partially fouled.

 

[ghiribizzo]

@RichieToye Yes, the plugs may look ok. But don't go looking for complicated solutions first.
Change plugs. If there is no difference, put those new ones back on the shelf and its only cost you half an hour and plugs you can use later.
If changing plugs cures it, you'll be a happy bunny.

 

[alex_rsa]

The coils are actually the spark plug "caps"

 

[bikerider007]

thanks alex, i have changed my plugs but no difference

 

[alex_rsa]

Now try the coils one at a time (ie disconnect 3 of them). Be careful disconnecting them from the harness as the clips are brittle in the cold weather.

You can just split the coil from the rest of the wiring at the small clip rather than having to pull the coil off the plug.

 

[bikerider007]

Thanks Alex stupid question time um i only have 2 s/plugs-coils????

 

[Ojay]

The plugs look ok, i have reset the TPS, i think ill now try the coils as it seems they might be the issue and their not coping with the load as the throttle increases - any more thoughts?

Had the same running problems on my 05 GS back in May... clogged K&N... stuck a standard air filter back in been running fine since...