BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]

1Back to top Go down   K75 doesn’t start Empty K75 doesn’t start Tue Mar 07, 2023 4:05 am


New member
New member
Hello, my bike has the same problem in this video

It start if i put it in motion to push and everything is okay. 
Could it be the starter relay? 
Thank you


2Back to top Go down   K75 doesn’t start Empty Re: K75 doesn’t start Tue Mar 07, 2023 12:39 pm


Life time member
Life time member
If that is what you are seeing and hearing, your sprag clutch is not engaging.  This is a fairly common problem caused by owners who don't change the oil frequently enough and there are many threads here addressing it. 

There are several ways to treat it, that involve cleaning the sprag itself.  A search of the threads where these techniques are discussed will let you decide which way you want to go. 

The problem is mainly caused by dirt in the pawls of the sprag that prevent them from "flopping over" to engage. 

I corrected the problem in one of my bikes by draining a quart of oil and replacing it with a cleaner like Seafoam and push starting the engine.  Go for a ride for about an hour being very easy on the engine(the oil has been diluted) and drain the oil when you get back.

Then refill with a good 15W40 oil made for diesel engines(Shell Rotella T6 is my favorite).  This has a lot more detergent for cleaning up the soot that gets in those engines.  Run for a normal oil cycle(I go about 5000 miles) and go back to your usual oil.

If you have trouble push starting, there is a lot of information on cleaning the sprag with spray to get the engine running.  Still, when you do, you want to do the Seafoam flush and diesel refill.

Present: 1991 K100RS "Moby Brick Too"
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175

3Back to top Go down   K75 doesn’t start Empty Re: K75 doesn’t start Tue Mar 07, 2023 1:49 pm


Life time member
Life time member
In the meantime, try having the bike in gear and rocking it backwards before attempting a start. Sometimes that will help. And if that does work then it's pretty good confirmation that it is a dirty sticking starter sprag that's your issue.

K bikes are pretty easy to push start. TURN THE IGNITION ON. Put it in SECOND gear. Have the clutch pulled in. If you're on a hill then just roll until you're going a few MPH(kph) and then the let clutch out somewhat quickly but gently. Or have somebody push and then let the clutch out when you get rolling.  Once you it does begin to start pull the clutch back in, rev it a little to confirm that it's running and then re-engage the clutch normally.

You don't to be going extremely fast to push start a K. A jogging pace should suffice.

Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT

Sponsored content


View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum