Dragging? starter

Hello all,

I have an 08 R1200RT, 24K miles. For some time now it has bogged on start, some times are worse than others. It presents as a low battery. If I stall the bike in traffic it will not start for a few moments, then just barely. I thought it was a failing battery so I replaced the battery with no improvement. Now I am guessing it is a bad starter. What say you?

Thank you in advance for you collective wisdom.

Overbyte

Overbyte...It's possible the starter may be going bad....but its pretty common they get dirty and start to drag. Here is a link than I used to fix mine. When I cleaned mine it performed as new.

Some do fail and someone else will tell you about some of the aftermarket starters. I realize you are asking about a different bike but suspect closely related..

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=816545&page=1

Another thing you can try is adding another cable from pos. lead on battery to rear post of starter and try.

Sometimes the cables get cooked. I used to put double cables on my Ducatis.

I have an extra starter if you end up needed one.

Mark

Hello all,

 

I have an 08 R1200RT, 24K miles. For some time now it has bogged on start, some times are worse than others. It presents as a low battery. If I stall the bike in traffic it will not start for a few moments, then just barely. I thought it was a failing battery so I replaced the battery with no improvement. Now I am guessing it is a bad starter. What say you?

 

Morning Overbyte

I have seen a few 1200RT's do that (including my personal 1200RT). In most cases it is just a low battery, or battery low on total cranking power.

I know you installed a new battery but even new batteries can be defective & some are way overrated as far as cranking power goes.

What battery did you install???

I guess if I was looking for your problem I would ride the bike to get it hot, then ride it back home & while it is hot soaking for a short time get some jumper cables ready to jump from another bike or automobile.

Then try to re-start the engine & if it drags then "quickly" jump it from a non-running motorcycle or automobile. If that shows something obvious then you will have a sort-of direction to look at.

If jumping doesn't help or completely help) then look into a starter issue, or battery cable with high resistance.

If you suspect a battery cable resistance issue then run a quick battery cable (both + & -) cranking voltage drop test.

You might also rig up your voltmeter to monitor battery voltage (ie charging voltage) while riding as your battery might not be getting a full charge from the alternator. (if it acts up more while riding in traffic & using the brakes then that more points to a possible battery charging issue). BMW released a slightly shorter alternator belt for some of the 1200 engine bikes due to some reported slippage. (usually a noise issue but I suppose it could also cause low charging)

I guess bottom line here: you (first) need to eliminate the battery itself, then eliminate possible battery cable voltage drop (1200RT has pretty hearty cables though), then eliminate any on-bike riding charging issues, then if still a problem go after the starter. If after all the above & you still have a problem then look for ultra high compression due to carbon buildup (do a hot engine cranking compression test) or something in the engine getting tight when it gets very hot.

Great, plenty of action items for me to try. How refreshing to have some diagnostic information rather than just throwing cash at the problem. I will let you all know what I find.

Thank you one and all. This has to be to most knowledgable and gentlemanly forum ever.

Overbyte

OK! I think I have found the problem.

I rung out the battery cables, did the volt drop test, all checked OK.

On a hunch I loosened the cable connection to the starter and sprayed with contact cleaner, then re-torqued the nuts.

Viola, no dragging starter.

I wish I had done that before I bought a new battery.

Thanks again to one and all for the help.

You restore my faith in mankind.

Overbyte

OK! I think I have found the problem.

I rung out the battery cables, did the volt drop test, all checked OK.

On a hunch I loosened the cable connection to the starter and sprayed with contact cleaner, then re-torqued the nuts.

Viola, no dragging starter.

I wish I had done that before I bought a new battery.

Thanks again to one and all for the help.

You restore my faith in mankind.

 

Morning Overbyte

Hopefully that eliminates your problem.

If you checked the (+) cable voltage drop between the battery (+) post & the starter's large stud then that should have showed any resistance in that connection that you cleaned. So if you did the voltage drop test that way then I have my doubts that your problem is completely gone.

On the other hand IF you checked the (+) cable voltage drop from battery (+) post to the large ring terminal on the starter end of the (+) cable then that could have missed that cable to stud resistance & there is a good chance your connection cleaning eliminated the starter dragging.

Happy cocktail hour Dirtrider,

I am sure you are right, I probably checked volt drop to the terminal ring rather than the starter post.

Live and learn.

Overbyte

So, here we are again friends. I thought I had if fixed but alas, it is not to be. (I think Dirtrider saw this coming.) I believe I have isolated the problem to the starter. Battery OK, cable OK and cable/starter connection OK. Now I have the starter out and cleaned. There is no damage that is obvious to me, but it feels pretty stiff to turn, perhaps bearings? Also, the brushes don't look too good. What is you collective wisdom? I am not very interested in OEM part$. Should I: go to a starter shop and have it rebuilt? Buy a salvage part from Ebay? Try to overhaul it myself? Or some option I haven't thought of...

Eagerly awaiting your collective advice,

Ovrbyte

I believe I have isolated the problem to the starter. Battery OK, cable OK and cable/starter connection OK. Now I have the starter out and cleaned. There is no damage that is obvious to me, but it feels pretty stiff to turn, perhaps bearings? Also, the brushes don't look too good. What is you collective wisdom? I am not very interested in OEM part$. Should I: go to a starter shop and have it rebuilt? Buy a salvage part from Ebay? Try to overhaul it myself? Or some option I haven't thought of...

 

Evening Ovrbyte

Any signs that the armature was dragging on the field shoes? (this is a big cause of hot engine starter dragging)

How about the commutator segments? Are they discolored or signs of poor brush contact?

A starter shop is an option as without a growler (or access to one) you won't be able to fully check the armature.

If you feel like pulling the starter a few times if the first try doesn't repair the problem then just clean up the commutator & install new brushes, then verify the bushings are good. If that works then you did good-- but if it doesn't & you can't find a smoking gun then you WILL have that starter out again.

If you have a GOOD automotive electric shop (starter shop) in your area then possibly have the starter tested.

If you need starter parts then try __ http://www.euromotoelectrics.com/

I would clean up the starter with some spray electronic cleaner and replace the brushes if they are worn down. A place you might try for electronic parts is http://www.euromotoelectrics.com. If they have the brushes they will be in stock also starters if you want and at better prices than the dealers. Good Luck!

I second DR's suggestion on euromotoelectronics. I had a hot start problem, but it was different than yours, you would push the start button and nothing would happen. Anyway, I bought one of their starters for around $100 and it eliminated the problem and has worked great for the last 15K miles.

I removed the starter - again. This time I sandpapered the cable - starter contacts, even though they looked clean. On reassembly it started as it should, sweet!

The first time I removed the starter, I looked at the contacts and they looked clean so I sprayed them with contact cleaner and retorqued. It worked OK for a few starts then went back to the dragging starts.

I think that there was just enough corrosion to make a high resistance connection. Obviously this is a critical connection.

Thanks to all for your thoughtful comments and suggestions.

Overbyte