R1100RT will not turn over, suggestions on the culprit?

[Teefour]

I bought a 2000 R1100RT over the winter. It's been running pretty solidly other than a battery that won't hold a charge for more than a week, resulting in the occasional ABS fault that goes away once I ride for 20 min and restart the bike. So a few days ago I go to start it up, and it won't turn over. My immediate thought was that the battery finally gave out and just doesn't have the juice to turn the engine over anymore even after a full charge.

 

So I replace the battery with a Yusa YT19BLBS. It needed replacing anyway. Install it successfully, give it a full charge (full according to my Deltran battery tender). Turn the key, lights come on, all looks good. Go to start it up, and its the same problem.

 

When I hit the starter button, I can hear a relay connect. The lights all dim down, so power is being pulled somewhere. Could this just be a short? Or are the starter motors known to go out on these bikes? Any specific places to start looking?

[CoolTouch]

You will need to remove the left tupperware to do this...

 

On the starter motor there is a spade connector. If you disconnect it and supply 12V from the battery that should make the starter turn the engine. If it does turn the engine, that should at least remove the starter from your possible culprits.

 

Electrical probs are always complex, exponentially more so online.

[AndyS]

The starter motor also may need to be removed and the mechanism cleaned.

Also, some of us have sufferd with the starter motor internal pole magnets detaching which cause this problem.

So try in order:

Check battery terminals

Check starter motor terminals

Remove motor and clean and check magnets.

 

[roger 04 rt]

+1 Remove the starter and inspect it. In addition to loose magnets there is an internal cover over the planetary gears that falls onto the armature, shorting it.

 

Here's a good link: http://forums.bmwmoa.org/showthread.php?69313-Valeo-Starter-Failure-Another-Cause-of-Failure

[The Rocketman]

A dead starter sounds very similar to a dead battery.

If it is the starter, an OEM Valeo starter brand new is only $62.88. Maybe 1/2 hour tops for you to install. If you can find a friend locally with a known good starter (and MANY BMWs use the same starter-see Valeo chart-below), you can try swapping it out first to confirm.

 

Get the starter here:

http://www.discountstarterandalternator.com/p-6416-brand-new-starter-for-bmw.aspx

 

[Teefour]

Thanks! Should I be getting the same voltage across the starter terminals as the battery terminals? Obviously only when the start switch is depressed.

[Teefour]

It ended up being the classic magnet separation problem. Two of them were totally chewed up beyond repair, which caused the motor to lock up while the solenoid still functioned. Guess I'm just buying a whole new one.

 

Thanks for the responses!

[mneblett]

It ended up being the classic magnet separation problem. Two of them were totally chewed up beyond repair, which caused the motor to lock up while the solenoid still functioned. Guess I'm just buying a whole new one.

 

Thanks for the responses!

Or just buy a replacement can/magnets: http://www.euromotoelectrics.com/product-p/d6ra-magccw.htm