BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

I've been riding my new R1150 R, 2002 for a few months now and I've noticed from the start what feels like inconsistent power output in my ride when I hold an even speed. I get into 2nd or 3rd and hold the speed there as evenly as I ever have and notice the feeling of the bike's power surging just a bit and falling back just a bit over and over.

It reminds me of the time I needed to replace the chain on my F650. There was a little jerkiness due the the chain being old and slightly locked in some areas, creating an inconsistent circle and a variance to the output of the bike. This is my first shaft driven bike, but I was expecting really smooth output, due to lack of chain.

I haven't noticed the problem at highway speeds, but during my city commutes where I don't get much higher then 3rd, I feel a jerkiness in the output when I hold steady. I find myself hoping that it has something to do with the feel of a single swing arm suspension (also new to me) on a bumpy surface. Maybe when the rigid shaft bounces the wheel leaves the surface of the road enough for it to spin faster, I surmise.

Well that's me wondering and guessing and hoping that this is just how these bikes feel. What do you know about this?

Oh dear. Do a search on 'Surging' or 'CCP' and watch the computer crash with the influx of responses.

A very careful valve end-float adjustment, valve clearance adjustment, TB adjustment, right plugs, possibly a TB balance tube, the most suitable CCP box, and the correct colour shoe laces will minimise this effect, but not always eliminate it.

It's normal, but doesn;t have to be intrusive. If the bike was running better earlier, it's probably just something that's gone out of whack. Or just live with it. It's a function of the R1150 engines in particular, not completely solved by the twin-spark update. The computer that drives the system samples at a slow rate compared to a ten-fold increase on the R1200x engines.

Tune-up time methinks.

Welcome wsykes.
You have discovered surging, and they all do that (TADT) to a greater or lesser extent.
I feel it is caused by the rudimentary fuel table used in our Motronic engine control system (computer) that constantly tries to adjust the fuel mixture too lean in response to the oxygen sensor input. While this reduces emissions and yields good gas mileage, it affects driveability.

There has been a lot written about this issue here and on other BMW motorcycle websites, and many have advocated removing the "CAT CODE" plug, but I think this could eventually lead to poisoning the catalytic converter by allowing the engine to run too rich.

After checking for air leaks around the intake manifold (including the rubber hoses attached to the bottom of the throttle bodies), the best way I know to reduce surging is with a good tune-up. If you get both cylinders breathing the same amount of air and fuel, it will run much smoother. This involves a careful valve lash adjustment followed by carefully synchronizing the throttle bodies. A new set of spark plugs will also help. You can do this with a manual and regular tools.
Two Tips: 1. Use the plastic spark-plug boot-puller that comes in your tool kit (if you don't have one, order at a dealer), and 2. Before removing the plug, blow air into the plug well and the front and back of the cylinder to blast the dirt out of there so it doesn't fall into the cylinder after the plug is removed.

Some riders say surging decreases/ceases after the bike is fully broken in (up to 20,000 miles), but that hasn't been my experience. When my valves and throttle bodies get out of whack, I still feel it after 41,000 miles.

The problem was largely solved in the 4-spark plug models, which introduced other problems (stick coil failures).
I'm fine making these adjustments to resolve the problem...they don't cost anything but my time.

Search this forum to find many fine threads about surging...

Sunbeemer wrote: Some riders say surging decreases/ceases after the bike is fully broken in (up to 20,000 miles), but that hasn't been my experience. When my valves and throttle bodies get out of whack, I still feel it after 41,000 miles.

Mine either. I don't cruise under 4000 on the freeway so it doesn't bother me so much. I've also found if you wack the throttle when leaving the stoplight, the surging is minimized. =) I've got 42k on the clock. I took the CCP out at 6k and that improved the surging a tiny bit.

I just installed the techlusion (gen3) in my 04 R1150R. I think it is helping in this surging issue. I can cruise at 3300is rpm and she seems to be taking it well - doesn't seem like working hard. Did not get as quicker as I hoped but then again, it is what it is.

My two cents...

Sanjay

Sunbeemer wrote: There has been a lot written about this issue here and on other BMW motorcycle websites, and many have advocated removing the "CAT CODE" plug, but I think this could eventually lead to poisoning the catalytic converter by allowing the engine to run too rich.

.

I doubt that - UK Rocksters were sold without a CCCP fitted.
US bikes tend to run lean thanks to California's exhaust emissions laws, and as far as I remember - most bikes imported to the US are setup to follow the California laws (For BMW it's easier and cheaper to make 1 bike setup for the US market rather than 2: 1 for California, 1 for all other states).

Thanks for all of the great suggestions. The bike has over 26,000 on her and was supposed to have been fully tuned up by the dealer before I picked her up a few months back. This is my first R1150 and I was worried something was wrong, but it's sounding like this is very common and sort of a quirk of this engine. I'll start fiddling with her when I get a moment and see if I can improve the situation, but I can deal with the tiny amount of surging I feel as long as nothing is broken.

Cheers!