Found this on an oilhead forum today, I know there are a few oilhead owners here, so I thought I'd pass this tip along to other members here .
The problem usually is hard start and stalling or stumbling after start on a cold engine .
Re: SOS - R1150R starting problem
by CycleRob ยป Sat Nov 16, 2013 2:32 am
Tony, The fact that you have no trouble starting a warm engine tells me your fast idle lever freeplay is most likely out of adjustment. The BMW specs list a cable freeplay measurement, but that does not take into account the wear in the cable and the plastic sliding ramp mechanism wear inside the throttle junction box attached to the airbox underside.
Here's a good test to see if yours is adjusted OK: with a hot idling engine push the fast idle lever ("CHOKE") to the first detent. You should immediately see 1,800+ RPMs. If you get less than that you need to adjust out the excessive freeplay at the top of the cable where it's attached to the left handgrip switch assembly. You could and should adjust it quickly while the engine is idling to find the maximum setting described below that will give you the throttle opening needed for a quick start.
First find the cable adjuster's rubber cover and slide it on the cable away from the top attachment point to expose the locknut and threaded adjuster. Use 2 wrenches, or 2 pliers tightly locked on to loosen the the locknut, then spin out the threaded adjuster 4 turns (exposing more threads). Next, to ensure making an in-gear turning maneuver with the fast idle lever on the first detent will NOT add some throttle, swing the handlebars lock-2-lock checking that the steeering motion will NOT raise the RPMs. Next, slowly move the start lever until it begins to raise the RPMs. Ideally you want the tip of the lever to travel just over a half inch (12mm) before the RPMs begin to raise, a setting that will give you great cold weather starts. If the adjustment is not there yet, keep going 2 turns at a time. When readjustments finally are excessive (usually the steering makes the RPMs rise) you'll know about how much to back it off to leave a little freeplay insurance. Finally, tighten the locknut and push the rubber cover over it till it stops. I guarantee the fast idle lever will show a noticeable change in the cold start when adjusted this way.
It's very common for this freeplay adjustment to be overlooked as normal wear ever so gradually makes it less effective at starting a cold engine . . . . and keeping it running on the start lever's first detent. Really cold weather with snow on the ground requires the start lever pushed to it's limiter stop PLUS several tiny throttle blips off the idle stop as you crank the ice cold engine's starter.
If the start lever adjustment turns out to not be the cause, another real possibility is the fuel you have been using is old and has lost too many of it's necessary volatile components. This is especially true if you are exclusively using Premium grade gasoline, which in today's weak economy fewer than ever motorists are using. The 10% Ethanol Premium fuel will also absorb more water over that longer storage period, making the fuel even less worthy. It's even more insidious when you remain loyal to the local station selling that stale product. Try a very busy major brand station and see if the cold engine start improves.`09 F800ST
EDIT :
Just did this to my oilhead, tightened the start cable adjuster 6 turns, it cold started like it did when I first got the bike .
