Bike dying at speed?

[Steve E]

Hi all

Took the Gs for a run today but had to return home early. As i was trying to overtake in top gear(60 mph) the engine faltered as if it was starved of fuel. quick down change and i managed to maintain speed. Bike would not accelerate past 70mph in 6th. Changing down the gears and the bike seemed OK then refused to accelerate past 80 mph. If i very gently accelerated the bike would speed up very slowly but far to dangerous to try to overtake anything. Bike was filled up this morning (15litres) prior to the ride.

Does any one have any ideas? Will try to get the bike to North Oxford Garage tomorrow.

Cheers
Steve E

 

[GSmonkey]

Had a similar fault on mine, hesitation with a handfull of throttle. Turned out to be a dodgy connection on the secondary spark plugs on the bottom of the cylinder.

 

[JohnnyBoxer]

Hi all

Took the Gs for a run today but had to return home early. As i was trying to overtake in top gear(60 mph) the engine faltered as if it was starved of fuel. quick down change and i managed to maintain speed. Bike would not accelerate past 70mph in 6th. Changing down the gears and the bike seemed OK then refused to accelerate past 80 mph. If i very gently accelerated the bike would speed up very slowly but far to dangerous to try to overtake anything. Bike was filled up this morning (15litres) prior to the ride.

Does any one have any ideas? Will try to get the bike to North Oxford Garage tomorrow.

Cheers
Steve E

Read this thread

http://www.bmwgs.com/forums/showthread.php?t=182764

Seems some other Hexheads have had it and BMW seem to be a bit puzzled in USA

The read is about a HP2..............essentially same motor, electronics and same problem

Goes on to mention your symptoms on 1200GS's too

 

[RickG]

blocked fuel filter or leaking fuel line within the tank = some juice at low loads, not enough when accelerating.

 

[HMR]

This problem happened to me three times when my R12GS -04 was brand new. It only happened after first driving for some time in constant speed around 120 km/h. The engine ran fine until I give some extra throttle to pass a car. Then the engine loose power as if it was short on fuel.

BMW told me over the phone that "It's either a contact issue on the lower sparc plug coils or it's a faulty spark plug". It proved to be a faulty spark plug.

It was very easy to verify knowing that the lower (secondary) spark plugs are only used at low rews. Below 3000 RPM or so. I just switched the upper and lower spark plugs with each other and the problem disappeared. Back home again I got two new plugs from the dealer. The problem never came back.

I guess that it was only one spark plug that was faulty but I never bothered tho find out which one.

 

[Paul Wakefield]

Steve,

Mine had the same symptom when the fuel pump started to go. I'd be a bit surprised if that problem was still around but maybe.

May see you at NOG later today.

Paul

 

[marcus]

I had a similar thing, fixed at 1st service

"wrong spark plugs fitted during manufacture"

 

[Steve E]

Hi folks and many thanks for the advice/suggestions.

Took bike into NoG this AM. After putting bike on diagnostic check they came upwith the spark plug coils breaking down. I now have 4 new sparkplugs and coils fitted plus an electronic gizmo for the fuel pump . Bike now runs smoother than it ever did, and is more responsive at the throttle.

Well done North Oxford Garage I can't thank these guys enough and i did'nt buy the bike there! Their customer service is 200% .

Steve

 

[Dahoum]

great to hear some good dealer feedback - and great to hear the fault was easily fixed Steve

 

[HMR]

Took bike into NoG this AM. After putting bike on diagnostic check they came upwith the spark plug coils breaking down. I now have 4 new sparkplugs and coils fitted plus an electronic gizmo for the fuel pump .

To me this sounds more like "we don't have a clue so we replace everything". Well who cares? The problem is gone...