Well damn.... Just spent 20 minutes writing out an intro on a tablet, and trying to insert a picture at the end just caused the page to refresh and loose it all...
I am Dan from south wales, i got my 1989 k100rs about a year ago. I have visited this site on a number of occasions through google searches as my usual mechanic "doesnt work on tractors" and i have had to do maintenance i usually dont feel safe to attempt. (I am historically un-mechanical)
According to the engine stamp the engine was made in 1986 so i dont have the record i suspect that 1989 was date of first uk registration, it has a 7-digit vin (weird right?) Bmw suppliers can access the system with it, and some just get error, anyway currently i am enjoying the exquisite feeling of finding my coolant drain plug mashed and before i take the grips to it and wrestle it off i should get a replacement first otherwise my bike is a very heavy garden ornament, and theres not many shops i can walk to to find a replacement bolt once i got it out the check the length, width n thread, i do worry bmw used a bolt that is completely unique to them.
If anyone knows a part number for the coolant drain plug for a 1986-1989 k100rs i would be highly appreciative.
I will be staying around as i refuse to sell a bike, and i need alot of help learning how to do more self maintenance, content you can expect from me is requests and/or gratitude, i am not educated enough to give any advice, and any i am foolish enough to offer will more or likely be detrimental.
Maybe i should say something about me and not the bike but i dont want to loose all ive written.
I hope the picture works,
Dan out,
Thanks all.

Hi Dan,

See part number ENA19112 (BMW P/N 07119904393)

https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=40&Ct=GA&SbCt=BA_15_40_GA_75&spPage=2

And according to MAXBMW it's M10 x 1mm pitch (item 16)

https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=51752&diagram=11_1974&partnumber=07119904393

The same part is called for on the cylinder head cover.

Mike

Thank you so much Mike D, a really big help.
Ordering that dude in right now, have ordered from motorworks before, they are really quick i have found, even with todays situation.
Thank you again Mike

Hi Dan,

If you have not used the parts list links before, then you should make a note as they are a good source. Another is Realoem, where you can see when part numbers were superseded.

You may have even been able to pick one up from the likes of Halfords.

Mike

Hi Dan

Bugger the coolant drain plug - let it corrode in peace. Pull the hose off where it joins the oil/water pump - drains the coolant in about thirty seconds flat as opposed to waiting half a day. Most of us here do exactly that. It'll give you the opportunity to check the waterpump spigot too as the chances are it will have a layer of aluminium oxide on it which will need cleaning off (and inside that part of the hose too).

Well snap, thanks for that little hack there Dai, i looked and i am convinced i see the one your talking about. Ive already ordered the screw but i'll just keep it for if i ever find myself near the cylinder head cover. Thank you both for your quick and helpful replies.
I realise i did not say although it should be apparent by now that i did not mod this bike, no i was looking for a 1000cc bike with a reliable engine and preferably without a chain and into my life walked this little gem. Yes so i bought a bike modded by an unknown party on a bmw bike :insert jokes about my naivety here: Yes i had no idea what i was getting into, my road bike history consists of honda hornet 600, suzuki sv650, yamaha ybr125 and aprilia europa 125 so no real bmw experience and i dont hold a car license so nvr encountered them much.
Thank you both Dai and Mike D for your help, it very appreciated.
Take care n stay safe.

There are two positions on the head. They are to blank off some oil gallery drillings, and will probably be loctited, so will need warming up should you ever need to go in there.

Mike

Welcome Dan

Dai wrote:Hi Dan

Bugger the coolant drain plug - let it corrode in peace. Pull the hose off where it joins the oil/water pump - drains the coolant in about thirty seconds flat as opposed to waiting half a day. Most of us here do exactly that. It'll give you the opportunity to check the waterpump spigot too as the chances are it will have a layer of aluminium oxide on it which will need cleaning off (and inside that part of the hose too).

Exactly that...slacken off the hose as said.

If the drain plug is scrap maybe a sensor and temperature gauge should go in instead....

Still an interesting look to the bike. Personally after my first K100 I've preferred the K75's. Less heat and feels more manageable in Calif. hot season. Still a very nice look.

Welcome Dan (one from 'down under')
I haven't posted for sometime, so thought I'd check out our newest member for starters...
Hope you can make the most of the rest of your South whales summer..