Starter Sprag Clutch - BMW Luxury Touring Community
LinkBack Thread Tools Display Modes
post #1 of 4 Old Nov 17th, 2005, 10:55 am Thread Starter
Join Date: Jun 2004
Posts: 575
Starter Sprag Clutch

Some of you may remember I had an intermittant problem with the starter sprag clutch. You push the starter button, the starter spins, but does not engage the engine. Here is my post from a while ago and I have followed with an update.

"2 oil changes ago I tried spraying the sprag clutch with brake cleaner, ran the 12,000 mile AMSOIL till hot, drained and put in fresh AMSOIL motorcycle oil and filter. The starter worked fine for 11,000 miles on that oil change. Not sure if it was the brake cleaner or the fresh AMSOIL that temporarily cured the problem.

I tried the CD-2 (obtained at WalMart) at 11,000 miles into my current AMSOIL motorcycle oil change because the starter sprag started slipping again. It seemed to work for about 800 miles, then the starter started slipping again. I just now changed my AMSOIL and filter and will see if this alone works. My guess is that it will for another 10-11,000 miles and as the oil gets dirty the sprag clutch will again occassionally misengage. "

UPDATE: That last oil change went 13,600 miles without a starter problem. Before I began using AMSOIL, I used the BMW and Mobil1 motorcycle oils with 6,000 mile oil changes and never had a starter problem. I switched to AMSOIL for the 12,000 mile oil changes and began having the starter problems 11,000 miles into the oil changes. I guess the sprag clutch was getting contaminated and took a while for it to get "clean". I just now changed to the new MCV AMSOIL and will run it 12,000 miles and see how it compares to the old AMV formulation. My 2000 K1200LT now has 127,000 miles. And my oil level sight glass has gotten cleaner, so I am presuming the AMSOIL is cleaning up some the sludge/varnish caused by the other oils, probably the Mobil1 as my mechanic says the worst sludge he has seen in motorcycle engines has been from Mobil1, and it was my preAMSOIL oil.

My suggestion to those who have these starter problems is to change your oil immediately to a high quality synthetic motorcycle JASO MA oil (AMSOIL worked for me) and see if the problem goes away. Much better than spending all the time and money in sprag clutch replacements. If you can't immediately change your oil and the spinning starter problem doesn't go away after repeated starting attempts, put the bike in gear and rock it some. If that doesn't work, try to push start. These all worked for me. Then try an oil change.
TimVipond is offline  
Sponsored Links
post #2 of 4 Old Nov 17th, 2005, 1:23 pm
Senior Member
murray's Avatar
Join Date: Feb 2003
Location: Stroudsburg, PA, USA
Posts: 1,831
Thumbs up

Tim, I also developed the sprag clutch syndrome at 60,000 miles. Took your advice and dumped in a bottle of CD 2. The problem was solved for about 11,000 additional miles then resurfaced. I use BMW synthetic oil. I change the oil every 6,ooo miles. Added another bottle of CD 2, Problem resolved. I will add the last 4,500 miles prior to the starter problem I rode in under 72 hours. The oil definitely had a workout. I will be replacing my clutch in about 1 week. the clutch does not slip but the oil found at the junction of motor and trans suggests rear main seal leaking. Odometer at 73,500.

Thanks,, Pete Murray
murray is offline  
post #3 of 4 Old Nov 17th, 2005, 2:00 pm
Senior Member
Join Date: Mar 2005
Location: Round Mountain, NV, USA
Posts: 153
I've only experienced the sprag clutch slipping problem once. I dumped in a bottle of CD2 at the oil change and didn't have any recurrances during my recent 4100 mile trip. I'm planning on making the CD2 a regular part of my oil changes.

Round Mountain, Nevada

Current Bikes

2002 BMW K1200LTE (Silver)
2005 Triumph Speed Triple
2000 Harley Davidson Wide Glide
2008 KTM 530 Exc-r
1995 Suzuki DR350S
DarrellM5 is offline  
post #4 of 4 Old Nov 17th, 2005, 3:33 pm
Senior Member
dshealey's Avatar
Join Date: Apr 2002
Location: Dandridge (Near Knoxville), TN, USA
Posts: 12,165
Anything one can do to avoid having to replace the Sprag Clutch is very worthwhile!

I did replace mine once, and would not wish that job on anyone. It is a real WITCH to do. Much more work than just replacing pistons and rings.

I had used BMW synth from 18,000 miles (every 6000 miles) until about one oil change before the problem, when I had switched to Castrol Syntec full synth. Everything in the engine was VERY clean, and no measurable wear at 100,000 miles, but the cage of the sprag clutch had deposits on it, causing the sprags to stick just enough so they would not engage. The spinning sprag clutch assembly works like a little centrifuge, and the sprag cage catches the deposits allowing a build up.

I would certainly be one to recommend the CD-2, probably about every 24,000 miles, with hopes it would keep the deposits from building up in the sprag cage.

I don't want to achieve immortality through my work...I want to achieve it through not dying.

David Shealey
Dandridge, TN
EX: '01 Black LT, BAT BYKE (Totaled at 110,000 miles)
IBA SS, BB, BBG, 10/10ths.
No bike now, but maybe in the future.
dshealey is offline  

Quick Reply

Register Now

In order to be able to post messages on the BMW Luxury Touring Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
Clutch Replaced. And Now, Page 2... hschisler K1200LT 23 Feb 27th, 2007 7:22 am
Clutch Centring Bar PeteM K1200LT 28 Dec 9th, 2005 11:20 pm
One-time clutch slippage???? paulcbrowne K1200LT 7 Nov 12th, 2005 11:33 am
Dry clutch spline Repair zzmanron K1200LT 3 Oct 31st, 2005 6:39 pm
Clutch "bite" John_S K1200LT 14 Oct 31st, 2005 4:37 am

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome