High idle, dies with throttle '85 K100rs

[Dragwn]

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.

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.

[TimTyler]

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

[Dragwn]

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?

[Dragwn]

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.

[TimTyler]

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

[Elipten]

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.

[Dragwn]

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.

[Dragwn]

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.