Cant believe how hard it is to get starting right on my old K100 1987, its only done 27k miles but if I dont get the choke just right the bugger wont start. Even when the weather is nice and warm I try without choke thinking it will fire up - not a hope still have to give it a bit of choke.
I just about get to the stage where I run the battery (new) down and it will suddenly fire up, next day I can go to it and it starts immediately. Only had it a week so will soon get the swing of it I hope.

Done a service on it, new plugs, filters, oil, perhaps thats what is causing the problem - I've spoiled it and now its going to play up for a few months !

To be fair it was laid up in an old Barn for a couple of years until I found it and resurrected her.

I have two Ks and they both start differently.
Original bike 86RT I give choke, hit the starter enough to get the pump fired up to prime the system, wait 3 seconds and then she fires straight up.

Second K, 88 I have had 6 months. Bit of choke (maybe not needed but it is habit now), starter and off she goes.

Probably no help to you at all, but the wild turkey is telling me I need to reply to at least 5 posts before bed.
Next.

That bit about priming the pump and waiting for 3 seconds sound like a plan, will try that in the morning. Thanks

Mine starts up on first touch of the button, no choke or throttle, the only time I ever use the choke is in mid winter. Doesn't help I know but gives an idea of what some other bikes are doing.
Have you checked your plugs?

Bosch will tell you that the jetronic systems are not designed to be started using any throttle as that messes with the poor things brain and it has a hissy fit. The jetronic ECU is a very primitive thing by todays standard. My K100 I have since sold would not start with even the slightest throttle, even think about it and no start and the Ford I had with LE Jetronic was the same, any throttle and you could wind it over till the cows came home and no start.
The K75 will start at a mere touch and the K1100 wants to prime as RossKo was saying but the main thing is don't play with the throttle as it does upset them.
The think they call a "choke" is a way of increasing the idle so as to keep it running once started when its cold it does not enrich the mixture at all. I was led to belive some time ago that if the choke was pushed to the full on position that it would then enrich the mixture it does not do that. The mixture is enriched automaticly acording to temperature of the coolant and also when you touch the starter button untill it reaches an engine speed of 711rpm when the earth is removed from the start system so as to prevent accidental starter engagement while running.

Just tried the 3 second wait bit, didnt touch the throttle - started immediately. Think I am sorted thanks to you guys.

Like you say the slightest touch of the throttle and it aint gonna fire up no way.

Cheers all

Charlie