Hi All - Just purchased my first BMW (K100RS - 1986). I have come into motorbiking late (early-50s) and wish I had done years ago. 

The K100RS has been rebuilt and chopped by a PO and looks like a scramble rather than cafe racer. I have plans to smarten it up somewhat inc seat (bench seat over the current cafe racer single), new handlebar to bring it closer to me with my 50 year old back. New controls (maybe motogadget or motone!) new forks and some general painting/powder coating.

I have limited motorcycle knowledge but armed with the Clymer original maintenance manual and Haynes manual and this forum I feel pretty confident about tackling most things. 

FIRST PROBLEM - Can't get past around 2,000rpm and bike cuts out at will. Lacking power throughout. Jerky and revs at will with no throttle applied. I have replaced fuel pump and filter with spark plugs to be inspected and possible replaced. I will then move to the TPS which could be the culprit if faulty. 

Any thoughts/advice on the TPS symptoms??

Good to join the forum 
Thanks all.

WelKome to the forum, and best of luck with sorting the bike. We're glad to have you.
Member's Intro is just that. Best to post the trubs you're having in the appropriate section. This allows follow up and makes research easier later on for those with a similar issue. 
Cheers.

 sounds like air leaks/vacuum/leaks  in or around throttle bodies

sounds like some one may have tried to "improve" on what BMW spent millions building , best of luck with your new project some one here will have the answers

Welcome here. Put the model of your K in the profile. It makes it easier for us to help you as we pick up your questions in the technical sections.

There's a very good google search the forum facility on the portal page too, Have fun browsing though threads with similar issues.

Welcome to the forum.
Has the bike ever run properly in its current form? In other words could the problem be incorrect assembly rather than component failure?
Pics of the throttles/intake system could be useful. As Moriarti says this sounds like an air leak(s)

PS If you think it's the TPS then the bike will run quite happily with it disconnected - an easy check.

PPS I'm going to stick my neck right out here and guess it's the AFM mounted on its side or something - I once tried that and found it's a complete no-no  .

hello GraydoK100RS

Hi,

to this forum!


Bernie