Clutch momentarily grabs on engine start

[BMUU]

I have a 2000 R1100RT with around 60k miles on it. Recently I’ve noticed that if the bike is in gear when I start the engine, the clutch will grab for an instant even with the clutch lever fully pulled in. This seems to occur most frequently when the bike has been sitting idle for several days. At all other times the clutch seems to operate normally and the bike shifts smoothly. The cable slack is properly adjusted and the clutch engagement point hasn’t changed.

 

Any idea what might be causing this? Is this something I should be concerned about?

 

Thanks.

 

[realshelby]

The key here is that it is more likely to do it after sitting several days. If you are not having any problems with it other than the first time when started I don't think there is a thing to worry about. Probably effected by the temps/humidity also. Drum brake shoes can do this. The lining is "sticking" to the flywheel/pressure plate. Might have a build up of gunk on it that promotes this. If it bothers you, I would try taking off the starter and with the clutch lever pulled spray some brake cleaner on both sides of the disc as best you can while you or someone turns the rear tire to rotate disc ( transmission in gear ). That might clean it up some and reduce or eliminate the symptom.

[dirtrider]

Afternoon BMUU

 

Difficult to say what your are dealing with.

 

It really shouldn't be doing that though. I have had them sit all winter & not have the clutch grab upon starting.

 

A few things come to mind.

 

 

First, is rust or corrosion build up on the clutch parts causing the driven disk to momentarily stick to the driving plate. (but you would think that would also cause issues at other times not just on initial start up)

 

Or, worn trans splines allowing the driven disk to hang in contact with the drive surfaces. (again, you would think that would also cause issues at other times not just on start up)

 

 

Or, excess crankshaft fore/aft movement in the bearings allowing the crankshaft to move away from the clutch push rod at engine startup.

 

On the above it would quite easy to remove the front plastic engine cover & push/pull on the front belt pulley to see how much crankshaft movement you have.

 

[dan cata]

I doubt there is any dirt/oil that makes the clutch grab even if it was disengaged... There is a serious amount of sticking force needed for this.

 

What @DR mentioned seems more plausible, although this is the first case I heard/read about.

 

Oh well, it's still winter, there is plenty of time to take the gearbox off the engine and inspect stuff in there, and lube the splines...

 

Dan.

[Quinn]

I'm wondering if the clutch isn't dragging all the time. You can put it on the center stand, pull in the clutch and shift into first gear, and see what the rear tire does (two people required).

 

-----

 

 

[BMUU]

Thanks for the replies. Terry’s idea of pulling the starter to get a look at the clutch plate is a good one and I’ll probably do that this weekend. I just replaced the alternator belt in late summer and all seemed well, there was no excess fore / aft movement or slop of the crankshaft, so I don’t think that’s the problem.

 

With the bike in gear, the clutch disengaged and the rear wheel off the ground, the back tire doesn’t budge after the engine is running. I actually did this test before I posted my original message. I thought there might be a clutch adjustment problem, but that doesn’t seem to be the case.

 

I guess that leaves a sticky / dirty / rusty clutch assembly, or a problem with the splines being worn or needing lubrication. I think I read somewhere that it is possible to lube the splines through the starter motor opening, without removing the transmission. I wonder if anyone has done this. It sounds kind of sketchy, but would be a whole lot easier than removing the transmission. I have no problem doing minor maintenance myself, but when it comes to pulling the transmission, I’m kind of out of my league. Good for my local dealer, bad for me! On the other hand, I don’t want a minor problem to turn into a major one, so one way or another; it’s going to have to get done.

 

I guess I was hoping to get a bunch of replies telling me this was normal and all 1100RT’s behaved like this! No such luck! :-)

 

 

[Alfred02]

My suggestion would be to ride the bike and just slip the clutch gently a few times and see if this doesn't fix it.

If it has build up rust/corrosion it will shave it off.

 

I have had this on a car that was parked for 6 months.

Did the clutch slip 1/2 a dozen times and it came good. Was fine after that.

If any of the components are stuffed, you are not really hurting it anymore.

What do you have to loose?

[philbytx]

Asking the obvious, and the cheapest first:

- You did adjust the clutch cable at both ends per the manual, right?

 

- When disconnected from the lever and the actuating arm, the cable does pull smoothly from BOTH ends?

 

Just sayin'

[BMUU]

My suggestion would be to ride the bike and just slip the clutch gently a few times and see if this doesn't fix it.

If it has build up rust/corrosion it will shave it off.

 

I have had this on a car that was parked for 6 months.

Did the clutch slip 1/2 a dozen times and it came good. Was fine after that.

If any of the components are stuffed, you are not really hurting it anymore.

What do you have to loose?

 

I'll give this a try when I can get out on the road again. We got 6" of snow last night and more on the way tomorrow, so I think it's going to be a while! Stop to think of it, I can probably do this in the garage, just holding the front brake. I'll give it a try.

 

Thanks.

[BMUU]

Asking the obvious, and the cheapest first:

- You did adjust the clutch cable at both ends per the manual, right?

 

- When disconnected from the lever and the actuating arm, the cable does pull smoothly from BOTH ends?

 

Just sayin'

 

I adjusted the cable on both ends per the book. I didn't actually remove the cable, but everything seems to operate freely and smoothly.

[Galactic Greyhound]

Asking the obvious, and the cheapest first:

- You did adjust the clutch cable at both ends per the manual, right?

 

- When disconnected from the lever and the actuating arm, the cable does pull smoothly from BOTH ends?

 

Just sayin'

 

I adjusted the cable on both ends per the book. I didn't actually remove the cable, but everything seems to operate freely and smoothly.

 

I believe that there was a BMW Service Instruction issued changing the clutch adjustment at the handlebar adjuster/lever freeplay from 10/5 mm to 12/7 mm. It was issued re something to do with clutch operation. Might make a difference if you are using the old figures.

[Trullion]

That's correct, though I doubt that it would make much difference to this issue, which definitely is not normal. Dry clutches don't usually stick (unike my old Triumph, on which in the time-honoured fashion I have to free the clutch using the kick starter for the first ride of the day). I would go with the advice already given by Alfred02. It wouldn't do any harm to remove the starter and have a look. You could measure the clutch lining thickness while you're in there - service limit is 4.5mm.

[Dave Parry]

How come you can start the engine with the bike in gear? Mine has to be in neutral to start even with clutch held in, (1999 R1100RT) Come to think of it, why are you starting it in gear anyway?

 

Dave.

[Boffin]

How come you can start the engine with the bike in gear? Mine has to be in neutral to start even with clutch held in, (1999 R1100RT) Come to think of it, why are you starting it in gear anyway?

 

Dave.

 

One of the differences between the 1100 and the 1150. Many folk have also converted the 1100 to do the same. Very useful should you stall the engine in traffic.

 

Andy

[Michaelr11]

How come you can start the engine with the bike in gear? Mine has to be in neutral to start even with clutch held in, (1999 R1100RT) Dave.

Your clutch switch is not working. You should be able to start the bike with the clutch pulled in when it's in gear.

Part # 04 61311459569 SWITCH

[Dave Parry]

I don't think 1100's do that unless they've been modded -- 1150?

 

Dave.

[outpost22]

I don't think 1100's do that unless they've been modded -- 1150?

 

Dave.

 

My '96 starts in gear with no mods that I'm aware of.

[BMUU]

How come you can start the engine with the bike in gear? Mine has to be in neutral to start even with clutch held in, (1999 R1100RT) Come to think of it, why are you starting it in gear anyway?

 

Dave.

According to the schematic provided in the service manual, this is normal, at least for the 2000 R1100RT. As long as the side stand is up and clutch is pulled in, it will start. In my case this is essential because my neutral switch is intermittent. I always figured I'd have it replaced when it was time for a new clutch, which may be now.

[jviss]

I don't think 1100's do that unless they've been modded -- 1150?

 

Dave.

My 2001 does, no mods; requires sidestand up, clutch held.

[Dave Parry]

Maybe it's a UK thing then?

 

Dave.

[Galactic Greyhound]

How come you can start the engine with the bike in gear? Mine has to be in neutral to start even with clutch held in, (1999 R1100RT) Dave.

Your clutch switch is not working. You should be able to start the bike with the clutch pulled in when it's in gear.

Part # 04 61311459569 SWITCH

 

Dave,

 

Michaelr11 is correct - your clutch switch has gone. You should be able to start your UK R1100RT in gear as long as thw side-stand is up and the clutch pulled in.

 

I just changed my faulty clutch switch this winter - it must have been out for some time. The switch was stuck in the lever block - I got it out by cutting the cable close to the switch and using a 1/4" drive 11mm socket. The cable connector end goes into the nose fairing on the LH side about level with the LH indicator. You need to cut a few zip ties to free it - perhaps easier if you remove the black plastic dash panel. Copaslip the threads of the new switch before fitting and finger tight is enough.

 

Edit: Here's Doug Raymond's excellent wiring diagram - look at page 1 for the clutch switch:

http://www.mac-pac.org/wp-content/uploads/2011/01/R1100RT_Elec_Diagram.pdf

[Dave Parry]

Many thanks for that info. Ced, i'll check it out,

 

Dave.