Engine miss under load!

[finny]

During my last adventure to Tasmania my 2004 R1200GS has developed a miss under load occasionally. Loaded and two up midrange revs with a splutter. 24000 kms and will be in for a service shortly. Any ideas on what may be the issue? Cheers Finny

[marc]

Sometimes it's something as simple as a bad spark plug.

[finny]

Thanks i think do the service and plugs. Maybe something may turn up in diagnostics! When they are such a dream to ride the slightest hicup seems so major. Cheers start the process of elimination.

[portablejohn]

Finny,
I am new to these boxer engines, but I think Marc might be right. Something to look for is carbon trails (that look a little like micro sized lightning bolts) on the insulator part of the plug and/or on the inside of the caps or on the wires.
Might just be an older, fouled plug. When they start to miss, they also start to build up a lacquer on them from the unburnt fuel. I've had mixed luck trying to clean plugs (less than 50/50).

Possibly a restricted fuel delivery problem? Wouldn't make the engine not fire, but might cause some symptoms under acceleration... ?



John

[finny]

Thanks John
I am also new to the boxer and after many years and various brands of bikes it is an experience that i have not had. As you suggest i may change the plugs prior to the service to eliminate this area.
Thanks again Paul