K75 Gas Tank compatability

[Bokobob]

 :dunno  I have an 87 K75C, as manugactured although the fairing has been changed to a K100 standard following a bustup.  Anyway, I hope this is not the dumbest question ever asked, but it has been discovered that there is a slight leak in the gas tank and it is only apparent when the tank is half or more filled up..then very little is found...I'll be taking the tank off to see if I can find more specifically where its origin is....I hope to be able to make a repair..
if repair is not possible, I will likely go to EBay or other source for a used tank and that brings me to my question:  Are all years of the K75 gas tank interchangeable?  if not, please explain....

Thank you for your assistance..
(Yes, I would like to buy a more pristine bike, and am in the process of trying to find one, but even if I do, I am not going to peddle mine to someone without repairing the gas tank.)..

[TimTyler]

http://www.motobrick.com/index.php?topic=5056.msg31260#msg31260

[Bokobob]

Tim, that is a big help and clarifies a lot of things I didn't know about...
I  notice on ebay only one seller emphasized what years his tank was suited for...the rest sometimes said which year but did  not always name the suffix of which K 75 it was.

Many thanks,

[Bokobob]

So far not much luck on Ebay...lots of beat up tanks...priced a new one at BMW dealer today...Oh, my....$1100 for a bare tank and in primer....

Probably will first see if I can fix this one...It hardly leaks a bit, but now and then I find some gas on the left side under tank...

[jacksdad1963]

Following advice on here, I got a stick of Permatex steel fuel tank repair resin: just clean uo the crappy seam/ pinhole, then push in a glob of putty, then smooth off to a tidy finish, dead easy!  :clap:

http://www.ebay.co.uk/itm/like/331252581037?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=108&ff19=0

The kit I got was #GTR-1...don't know what difference there is!
I also added some brush on POR-15 sealer to all the interior seams, this was left over from a full POR kit I used on another bike: Looks like silver paint, just applied it whilst the inside was dry  :2thumbup: