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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Dragwn on March 21, 2015, 01:43:44 AM

Title: High idle, dies with throttle '85 K100rs
Post by: Dragwn on March 21, 2015, 01:43:44 AM

Had to call a friend with a truck tonight after my K died. It would start and had a high idle, almost 2k, but died immediately with any throttle.

The only things I could see with a flashlight were the hose from what looks like the crankcase under the left rear corner of the airbox was crushed and split wide open. This is the hose that goes to the plenum. (http://tapatalk.imageshack.com/v2/15/03/20/3db2584355b7ac6ba4a065661ffcdd5f.jpg)

I also noticed a vacuum cap was cracked on the fuel rail. I am thinking (dangerous I know) that the hose being fubar was the culprit. All other hoses are newer and the fuel filter is new, hoses inside the tank are good and fuel pump is good, oem bmw.

Title: Re: High idle, dies with throttle '85 K100rs
Post by: TimTyler on March 21, 2015, 03:11:05 AM

Crankcase breather hose. They don' t last more than a couple of years. But  a new one.

Title: Re: High idle, dies with throttle '85 K100rs
Post by: Dragwn on March 21, 2015, 03:21:06 AM

Tim, would this be causing the running issue? I know it obviously can't be good for the motor but would it cause the high idle/dying part?

Title: Re: High idle, dies with throttle '85 K100rs
Post by: Dragwn on March 21, 2015, 04:11:05 AM

Just ordered a new one from Beemer Boneyard, wish they didn't have a $20 minimum order though. Ordered a new oil filter and o-rings to get up to the $20.

Title: Re: High idle, dies with throttle '85 K100rs
Post by: TimTyler on March 21, 2015, 10:48:17 AM

Any air leak in the system will cause the engine to run like crap.

Title: High idle, dies with throttle '85 K100rs
Post by: Elipten on March 21, 2015, 12:15:29 PM

These bikes are between 20 and 30 years old.  Expect all rubber components to have or will fail due to age and exposure.  Sooner or later it will all need replacement.  Since I have money and no time, when I pulled my bike apart last year, I just replaced every rubber part could.  I don't like to screw around.

Title: Re: High idle, dies with throttle '85 K100rs
Post by: Dragwn on March 21, 2015, 12:18:36 PM

Before I bought this K a bmw mechanic owned it and replaced all the other lines but time and heat got to this hose first. Everything else looks solid and crack free. Going to spend some of today wrenching, some riding my Kwaka.

Title: Re: High idle, dies with throttle '85 K100rs
Post by: Dragwn on March 23, 2015, 08:36:49 PM

Parts from Beemerboneyard showed up today so tomorrow I will put it back together with the new hose and cross my fingers that is all I need. With my financial situation I am afraid I will have to sell the bike to stay even somewhat afloat as I was denied unemployment benefits.