Having a bit of a problem

[fleetwood]

With my F650 Funduro ( l reg 10,000 mls ) The bike starts fine and runs smooth on tick over, but give it any throttle and it runs very rough and backfires, have checked the usual stuff plugs, leads etc. one trick that does appear to help the problem believe it or not is to run the bike on full beam ??

 

[G.C.]

Petrol ?

What petrol are you using, no more than 95 octane ?
Its the most common cause of this sympton.
Not sure about the full beam though.

G C

 

[komatias]

It seems like an electrical problem more than anything seeing as you can run it fine with full beam on. there might be a short somewhere. My feeling is that the sparkplug isnt getting enough power to burn the fuel fully. Trace the light calbes back to the electrics box and test any fuses, connectors etc. You might want to dismantle the controls no the handlebars and spray them with some WD-40 aswell just to be sure.

Good luck

 

[walti]

Check that the inlet tract is fully sealed, no air leaks between carb/throttle body and head.

Poor gasket or similar.

 

[Trevor George]

Have you tried removing the metal spark-plug caps as per here ->FREE! 100% performance improvement. (Remove metal plug caps)

 

[fleetwood]

What petrol are you using, no more than 95 octane ?
Its the most common cause of this sympton.
Not sure about the full beam though.

G C

must change my avatar

 

[fleetwood]

Thanks all for helping out, much appreciated Trev your link sent me to a wealth of knowledge, turned out to be a tired voltage regulator thanks again all,

 

[Max_Kool]

Does this plug-cap trick also have any effect on modern F650GSes?

 

[fleetwood]

Does this plug-cap trick also have any effect on modern F650GSes?

seems to make a difference on some twin carburettor bikes (but haven't noticed any difference on mine)