K11 Owners Group

Randy Boyer · Joined: 05 Aug 2008 Posts: 5 Location: San Diego

I've got the '85 K100 stripped down for cleaning and paint, frame off and wondering whether or not I should go to the trouble to replace the head gasket. I've rebuilt the water / oil pump, seals were bad, and hoping tthe water pump was the cause of coolant in the oil. Not sure I know of any way to check the head gasket without actually opening the case up.

Any thoughts on how likely it is on this bike to have a head gasket go bad?
Is there a history of blown head gaskets for the k100 ?

Repairing now would be much easier than the alternative after everything is back together.

Thanks

duckbubbles · Posted: Fri Aug 22, 2008 4:34 pm Post subject:

Head gasket failures are quite rare. Unless the engine was severely overheated, I would not expect the gasket to be bad.

But for peace of mind and to be sure that you won't have to go in there again, you may want to do it. The good news is that is a fairly easy job, considering that the head is sticking right out at you.

You can check for oil in the coolant, also.

Frank
_________________
85 K100/1100RS, 321,000 miles, 25 years
96 Ducati 900SS/SP, sold it
05 R1200ST, 35,000 miles, 5 years
400,000 BMW miles

Flying Duck · Posted: Fri Aug 22, 2008 4:48 pm Post subject:

Moondog · Posted: Fri Aug 22, 2008 8:38 pm Post subject:

+2
Did it on mine couple years ago. Nothing wrong with it. Look else where. Unless you seriously overheated it and the risk of a warped head comes into play.
_________________
"Badges? We don't need no stinking badges"!

I like the social aspect of riding. Rally's, socializing, drinking beer, fartin' and carrying on. Smile

2004 R1150RS
1996 K1100RS (moved on to new home)

acftfliehr · Big Brick Rider Joined: 05 Nov 2007 Posts: 62

'85 k100, check the output shaft rivets as mine blew at 180 K miles..

Later output shafts you can install, but require extensive mods to the case for the aft (load/thrust) bearing.

If you want, reply to this and i will provide links to discussions on this...

Randy Boyer · Joined: 05 Aug 2008 Posts: 5 Location: San Diego

Sure, I'd be interested. Let me know anything that you feel would keep it running.

Thanks

acftfliehr · Big Brick Rider Joined: 05 Nov 2007 Posts: 62

Here are some previos threads concerning the issue...

http://f3.webmart.de/f.cfm?id=2385371&l=2&sr=176&r=threadview&a=1&t=3291608

The links in the article are quite good if you want to do this.

Looking back, the newer engine was probably the easier route, but I wanted to keep my machine "original".

http://f3.webmart.de/f.cfm?id=2385371&d=0&sr=276&r=threadview&a=1&t=3196029

My initial post..

The BMW part fiche is elusive on what main bearing goes on an updated shaft. Read it carefully and you will see the old bearing listed.

What I did, was take the old bearing off my old shaft and put it onto a salvaged newer shaft..

Good luck.