Starter spins but won't engage

[Scotty2]

:bmw:Starter spins but won't engage

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I have an 05 K1200LT with about 42K miles. The last couple of times I went to crank over a cold engine the bike's starter would spin, followed by a clunk. It sounds like the starter motor is spinning then the bendix gear is engaging after the starter has developed some RPM. I don't want to eat up my ring-gear so I'll need to drop the starter and inspect the bendix and ring-gears.
I guess my question is should I replace the starter motor or will I just be able to lube up the bendix gear / shaft and reinstall it? What kind of life does one see for a K1200LT starter motor?

Thanks,

Scotty2

[bigbear]

Scotty,
the starter spins and there is an internal sprague clutch that gums up on these bikes. Pulling the starter will do no good 99% of the time. The experts recommend running a good cleaning agent in your engine oil for a couple hundred miles and then changing the oil. Possibly even a couple of changes. I do not recall what brand of products are recommended but I would suspect doing a search on "Sprague clutch" would yield some results.

NOTE: From people who replaced this clutch, state that this is the first piece installed in the bike and the rest of the bike is built around it..

[paalao]

I had a simmilar problem with my car last moth, And it was the spark plugs that was failing, proberly soothed down or something. I had to put ignition on twice to give it fuel and then start it...and then it fired.

[jzeiler]

:bmw:Starter spins but won't engage

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I don't want to eat up my ring-gear so I'll need to drop the starter and inspect the bendix and ring-gears.
I guess my question is should I replace the starter motor or will I just be able to lube up the bendix gear / shaft and reinstall it? What kind of life does one see for a K1200LT starter motor?

Thanks,

Scotty2

There is nothing wrong with the motor. There is no bendix and no ring gear to chew up so press on. The gears are all meshed all the time. What you are hearing is the pawls of the sprague clutch grabbing. Varnish and gum build up (usually around 80,000 + miles) and the pawls hang up.

The only real fix is to do everything you would do for a clutch replacement and add another 5 hours of work to get to this sprague. Some have had luck removing the crankcase cover and squirting some cleaning agent into the sprague clutch housing. You can see it with the crankcase cover off but that is about all you can do.

[murray]

The only real fix is to do everything you would do for a clutch replacement and add another 5 hours of work to get to this sprague. .

I have done the sprag replacement. Actually once the clutch is removed all you have to do is remove the generator and intermediate case . So add another 1/2 hour to the job.

Try CD-2 detergent in the oil . Ride for about 200 miles non stop and drop the oil. This may get you by between oil changes.

[jzeiler]

Thanks Pete, I was just being on the conservative side. I am sure the dealer would add 5.

[murray]

Thanks Pete, I was just being on the conservative side. I am sure the dealer would add 5.
John I Agree , The only problem I had when changing the bearing was the actual removal of the bearing from the vacuum sealed bag. Seven of the microscopic springs ejected from the bearing. Took over a hour to reinstall the springs, A real Mo Fo.

[NascaLT]

I had a similar problem, used the CD-2 detergent cleaner and problem solved. For a few dollars it is worth the try.

[rocketman007]

I haven't been so lucky. I tried all of the cleaners and no luck. it may start 20 times in a row but the 21st always occurs at the worst possible time. So for the second time in 85k miles I have to replace the starter clutch. I think its because I over use the reverse, at 5' 6" tall I use it alot.
rocketman

[dshealey]

I haven't been so lucky. I tried all of the cleaners and no luck. it may start 20 times in a row but the 21st always occurs at the worst possible time. So for the second time in 85k miles I have to replace the starter clutch. I think its because I over use the reverse, at 5' 6" tall I use it alot.
rocketman
Using reverse has no affect on the sprag clutch. It is normally slipping all the time the engine is running anyway. When in reverse, no difference.

The sprag clutch is an "over running" type clutch that locks up when the starter motor is turning faster than the engine starter drive gear, so when the engine is stopped, the starter motor turns it over until it starts, then the sprag clutch releases and slips the entire time the engine is running. That is why you can keep the starter motor turning even after the engine starts with no noise or damage. When you use reverse, the engine is already running, so the sprag clutch is in it's normal slipping state, not different than when you are riding down the road.

[Scotty2]

Just wanted to say thanks to everyone for the information. The problem seems to have gone away for now. I will however try the remedies should it return. I'll also be sure to replace that booger when the clutch is gone.

thanks again,
See some of you in Utah for CCR

Scott

[dencla]

There's a recall for 05 models concerning that problem:
http://www.bmwlt.com/files/albums/userpics/10002/RCRIT-04V438-4687.PDF

[jzeiler]

Thanks for the post Denis, but that is a different issue where the alarm was cutting off the fuel pump. This is a starter sprage clutch issue.