kafflut
Puppy
- Joined
- Sep 11, 2013
- Messages
- 25
- Reaction score
- 0
- Bike
- BMW R1150GS
When my 1986 K100 warms up the idle revs go up to nearly 1500. It starts first turn and idles at below 1000. But when warm, it creeps up.
Here's what I've done and/or tried in order to try get idle revs down:
I have replaced all rubbers from the plenum down to the cylinder head, the crank case breather rubber to the plenum, vacuum take-off caps. Air temp sensor reading is okay. Coolant temp sensor reading is okay. Timing set properly. I have 2 K100s so I was able to swap out EFI and EI units and the fuel pressure regulator and the air flow meter. I also replaced the rubber from #4 vacuum take-off to the fuel pressure regulator.
It's not the throttle position switch - I've seen it called "idle switch" - the switch at the rear of the throttle body assembly that's supposed to "click" when you close off. That's perfect it works. And it's not the clamps on the TB rubbers preventing movement.
It's not the fast idle mechanism or cable and I disconnected the throttle cable.
I've tried various settings of the bypass at the air intake, the one under the tank and you remove the rubber grommet in the air filter housing to adjust it with an allen key.
I tested fuel pressure at the rail - it's fine.
The inter TB linkages are fine - those little screws that everyone tells you don't touch and if you do, throw away the TB assembly, drive a wooden stake through the rest of the mechanism and burn the bike.
The TBs are balanced
The throttle stop screw is adjusted for maximum shutness of the TB valves, the butterfly valves.
I read on other forums and found several owners of older K100 who have the same, revs go up when the bike is warm. I saw an unofficial BMW view along the lines of don't worry about it, ride the thing - it's only when you wait at a traffic light that it's a bit noisy, when you touch the throttle to pull off you're over 1500 rpm anyway.
I agree with the this why-bother view, but I'd still like to be able to get my idle revs down to about 1000 or at least know WTF is going on
Has anyone had this problem, solved this problem or suggestions to offer?
Here's what I've done and/or tried in order to try get idle revs down:
I have replaced all rubbers from the plenum down to the cylinder head, the crank case breather rubber to the plenum, vacuum take-off caps. Air temp sensor reading is okay. Coolant temp sensor reading is okay. Timing set properly. I have 2 K100s so I was able to swap out EFI and EI units and the fuel pressure regulator and the air flow meter. I also replaced the rubber from #4 vacuum take-off to the fuel pressure regulator.
It's not the throttle position switch - I've seen it called "idle switch" - the switch at the rear of the throttle body assembly that's supposed to "click" when you close off. That's perfect it works. And it's not the clamps on the TB rubbers preventing movement.
It's not the fast idle mechanism or cable and I disconnected the throttle cable.
I've tried various settings of the bypass at the air intake, the one under the tank and you remove the rubber grommet in the air filter housing to adjust it with an allen key.
I tested fuel pressure at the rail - it's fine.
The inter TB linkages are fine - those little screws that everyone tells you don't touch and if you do, throw away the TB assembly, drive a wooden stake through the rest of the mechanism and burn the bike.
The TBs are balanced
The throttle stop screw is adjusted for maximum shutness of the TB valves, the butterfly valves.
I read on other forums and found several owners of older K100 who have the same, revs go up when the bike is warm. I saw an unofficial BMW view along the lines of don't worry about it, ride the thing - it's only when you wait at a traffic light that it's a bit noisy, when you touch the throttle to pull off you're over 1500 rpm anyway.
I agree with the this why-bother view, but I'd still like to be able to get my idle revs down to about 1000 or at least know WTF is going on
Has anyone had this problem, solved this problem or suggestions to offer?
