BMWMCCWA

I have been rebuilding a 78/79 R1000 RS, I have got it running and idling ok, but when the motor warms up and I give a quick rev to about 2500 rpm it stays at that or will slowly settle back down to idle. I have put a rebuild kit in the carbs, new throttle cables with plenty of slack, new mounting hoses and clamps. Has any got any ideas how to fix this problem. Thanks Noel

Give Vince a call at Bassendean motorcycles, he should be able to point you in the right direction.

Have a look on ADV Rider and search for R100 Hanging Idle
There are a few good pointers given there, it could be dirt in the bean can causing the mechanism to stick or it could be balancing of the carbs. (which should only be done when bike is properly warmed up from a short 5km ride - garage warn up not sufficient)
When it hangs up did you check the throttle arm position on each carb to confirm both had closed?
You can also spray a fine mist of water over the rubber connectors between carb and cylinder head, if this makes the idle drop then there is a leak there.

Good luck
JonO

Thanks for the help bully and jono, I had a look at the ADV-rider site, seems a few other people have had the same problem, most of the remedies are either the balancing of the carbs, or the throttle butterflies are not sitting correctly. I have replaced the open points set up with an electronic ignition,the throttle arms are closing when the carbs are off the bike, and there this plenty of slack in the cables, i will try the spraying the mist of water over the rubber connectors before pulling apart, If all else fails I will give Vince a call.

Here is a useful link that may help http://www.advrider.com/forums/showthread.php?t=815779

I put new bars upon an 81R100 had simular problem.....the handlebar needed to be filed & emery papered down as the twist grip was fighting friction...low RPM's equal's low return spring pressure.
Guy

Another common problem is a broken strand in the accelerator cable on one side, which prevents the throw arm going all the way back down. But with these old bikes, I set them up so that they run at 1000 rpm when warm, ie they do not idle when cold

John