idle speed

[tbologne]

Can anyone advise as to what the normal idle speed for the Rockster is at normal riding temperature?

Mine idle's at around 800-900rpm, but I find that the bike runs smoother at 1100rpm when I leave the 'cold start choke lever' (located on left side of handle-bar) in the up position.

Appreciated,

T

[thenewcamus]

T,

Once its warmed up, the engine should idle at 1100 RPM with the fast idle lever OFF. You may need to adjust the idle speed with the BBAS (Big Brass Adjustment Screws) on the throttle bodies. Possibly even a full Throttle Body Adjust. Check out this link:

http://www.advrider.com/Wisdom/TBS4Dv1.0.pdf (requires Adobe Reader)

or

http://www.ibmwr.org/r-tech/oilheads/R1 ... sync.shtml

[Marku]

T,

Once its warmed up, the engine should idle at 1100 RPM with the fast idle lever OFF.

Mine idles exactly at 1000 RPM's with the fast lever OFF and it does "feel" a little low. Does it really matter?

[fnfalman]

My Guru (can't say his name or even who he works for because he's doing stuff for me outside of channel) set my Rock's idling at just a hair below 1000-RPM. It's slightly lumpy but he said that's where it's suppose to be. If it's idling too high, it may idle smoothly but it will also overheat the engine. Remember that you're riding an aircooled big twin. Also, the tach isn't 100% reliable as far as actually measuring correct RPM either. He hooked mine up to the BMW machine and adjusted the RPM from that readout.

[jeffbowman]

My Rockster has been idling at 800-900 recently, feels rough, and has even died a few times. The service tech at the local BMW dealership said 1100 is the target. Surely there is enough oil cooling and fine German engineering going on in there to prevent an overheat ... although my continual redlining might someday prove problematic.

[fnfalman]

Surely there is enough oil cooling and fine German engineering going on in there to prevent an overheat ... although my continual redlining might someday prove problematic.

The Germans didn't design the bike for "parade" duty, so I seriously doubt that they factored in the long idling times. Also in Europe, there are no silly ass laws against lane splitting and filtering, so the bikes don't have to crawl along traffic either. About the only American state that resembles European riding condition is California.

[jeffbowman]

So much for trusting the Germans.

Ahhh, that we could all live in California with the rest of everyone ...

For my '04 Rockster, my BMW service shop mechanic and manager recommend an idle speed of 1100 rpm and my Clymer Service/Repair/Maintenance Manual (M503-3) indicates 1050 - 1150 rpm, so if idling rough even a bit I'd bump to 1100 without thinking twice and shift worry to cylinder head scrape in the twisties.

[fnfalman]

and shift worry to cylinder head scrape in the twisties.

Most of the times, your peg feelers will drag first unless you go into a negative camber turn. That's when your cylinder head will touch the ground first.

Get better shocks (ie Ohlins) so that they won't get compressed as much during hard braking and hard cornering and/or put on the R1150GS paralever rod for more clearance.

After my guru fixes the tranny issue, I'll do the GS paralever rod conversion and the GS cams. Supposedly the GS cams lift the valves higher.

[boxermania]

Gentlemen

There is nothing magic about the rpm, it is merely a guideline, however, you will soon find out that 800-900 rpm is too slow and you feel the rocking of the pistons.

As yopu approach 1100 rpm the bike rocks less and becomes smoother in its cadence.

Anywhere between 1050 rpm and 1150 rpm where the normal shaking is at the minimum should be the rpm to shoot for.

[riceburner]

and shift worry to cylinder head scrape in the twisties.

Most of the times, your peg feelers will drag first unless you go into a negative camber turn. That's when your cylinder head will touch the ground first.

Get better shocks (ie Ohlins) so that they won't get compressed as much during hard braking and hard cornering and/or put on the R1150GS paralever rod for more clearance.

After my guru fixes the tranny issue, I'll do the GS paralever rod conversion and the GS cams. Supposedly the GS cams lift the valves higher.

the GS cams are the same as ours - you need the RT cams.


I've done the GS Paralever mod - although apparantly on this weekends run through North Wales the R1 rider behind me said I was still getting very close to touching something down!