I read that the older K's take leaded fuel, (i have an 84 rs) should i still add an additive or are the valves good now?

You have to give us your bike serial number.
Only the very first Ks took leaded fuel.

Bert

hey Bert, the Engine # is 104EA30841796, VIN i think is CHNK100RS0019065. date of manufacture was 07/1984. And where do you find the info re leaded or unleaded petrol?

Ta,
Tony

"Early K Series machines were designed for leaded fuel - this was changed sometime early in 1985 from the Chassis Numbers listed below.

K100 (UK) unleaded fuel from chassis number 0 007 291

K100RS (UK) unleaded fuel from chassis number 0 081 107

K100RT (UK) unleaded fuel from chassis number 0 024 999"

courtesy of : www.bmbikes.co.uk

Not sure how that translates to the rest of the world but I think Australian bikes are European spec.

Regards,

Phil

K100rs with chassis # starting at 0081107 (last 7 digits of the VIN) started to be manufactured in November 1984.
If the data posted on bmbikes.co.uk is correct, your RS takes leaded fuel.
You must put an additive in your gas.

My RT is in the same range and I have been using Nulon with no adverse effects but for all I know it could be red cordial so any preferences or is this another can of worms.

Regards,

Phil

Lots of different wisdom about this............. ...........some say you need to use a lead replacement as the valve seats are too soft (MOTOBINS in the UK do a head coversion) others say that if the bike has been running at least for about 30,000 km on leaded fuel the seats have sufficiently been hamered in with lead that you don't need to use it anymore. Important is that a lack of lead will show itself in the valve seats, leading to reduced valve clearance. I don't know, my K100RT is from 1984 and I use an additive, just to be sure. Cheers, Rene.