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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: k projekt on November 08, 2019, 03:08:35 PM

Title: White Smoke out Exhaust & Losing Coolant
Post by: k projekt on November 08, 2019, 03:08:35 PM
Afternoon Guys,

Went for a ride today and drove around 20miles, after returning I noticed that coolant was all over the back end of the bike near the exhaust.

After a quick clean and topping off the coolant, started the bike back up and there is a thick cloud of white smoke.

Any thoughts on this would be much appreciated, thanks.

Bike is a 1985 BMW K100RS.
Title: Re: White Smoke out Exhaust & Losing Coolant
Post by: Martin on November 08, 2019, 03:36:18 PM
It sounds like you've done a head gasket. Remove the spark plugs and check cylinders for water ingress. And while your there you can do a compression test. In any event the head will have to come off. With the head off it should be checked for warpage and you may as well check the condition of the valves and replace their seals.
Regards Martin.
Title: Re: White Smoke out Exhaust & Losing Coolant
Post by: John Lang on November 09, 2019, 07:12:27 AM
When you stopped to clean up the coolant did you use the side stand? Could explain the white smoke.
Title: Re: White Smoke out Exhaust & Losing Coolant
Post by: k projekt on November 09, 2019, 12:12:41 PM
Checked the spark plugs and they're all a nice chocolate color except the 4th one from the front. Cranked her up and got a little water to come through while the plug was removed.

Looks like it's the gasket after all, would anyone have any procedure/link that explains how to get to the gasket and make the change?

Appreciate the helps guys!
Title: Re: White Smoke out Exhaust & Losing Coolant
Post by: Laitch on November 09, 2019, 12:50:32 PM
Quote from: k projekt on November 09, 2019, 12:12:41 PM
. . . would anyone have any procedure/link that explains how to get to the gasket and make the change?
It's in the Engine section of the BMW K75 K100 2V repair manual at this link (http://www.motobrick.com/index.php/topic,11014.0.html). Also, consult the Haynes BMW K75/K100 manual at this link (http://motobavaria.com/docs/bmw_k100_and_k75_haynes_manual.pdf). A search of the site will uncover many posts covering aspects of this procedure.
Title: Re: White Smoke out Exhaust & Losing Coolant
Post by: daveson on November 09, 2019, 04:02:27 PM
It's possible, though unlikely, that the cause of a leaking head gasket is simply loose head bolts,  it only takes five minutes to check. Torque all bolts in the normal sequence. If any turned, you might have fixed it,  but monitor your coolant level, because you might have a stretched bolt or so.

Failing this, I have sometimes fixed a leaking head gasket by tightening the bolts three pounds more than the number in the book (after all,  that gasket has been squished for 34 years)

It takes more torque to start it turning than it is set at.