How can I tell from my Frame number if my 85 K100RT was Early, Mid, or Late Production?

There were changes I'd like to know about.
Like whether my K100 requires leaded fuel.

Gerry

If you enter the last 7 digits of your VIN here:
http://www.realoem.com/bmw/select.do
they will give you the month/year of production.

Leaded fuel? Thought that went out in the '70s for production vehicles. I also have an '85 and use brand name midgrade fuel.

Yeah, in the North American market leaded fuel was phased out in increments over time from the late '70s through the very early '80s. By about 1982 there was well less than 10% of the lead in a gallon of 'gas' than was there in say, 1977. But other markets stuck with it for much longer. It's an issue with too 'soft' valve seats and the valves faces themselves. If the clearances are going away rapidly after a shim adjustment, or the adjustments are too frequent, then there's an issue. If not, no worries. The lead, as most probably know, offered a sort of cushion to the contact of the valve against the valve seat. With less lead there would be much more heat build up and therefore potentially more valve face and seat wear. Most Japanese bikes had 'Stellite' treated valves and hardened seats which resisted the heat of unleaded petrol as far back as the '70s, ironically.

OK, heres what I found out.
There were 14,899 K100RT's made.
The unleaded gas change was phased in after frame # 24,999.
That makes mine OK for unleaded gas (phew!!!)

But heres a weird item.
According to the list my K100RT was made in July 1984.
Frame number is 500XX.
But the ststement says the change was made after frame # 24999 in January 1985.

My K is titled as a 1985.
???????????????????????????????????

Gerry

My 1985 K100RT was actually built in 12/84.
It's titled as a 1985.
Richard1

I suspect that title is granted when the bike was officially sold, as an example my bike whilst it was built in 1990 was not actually sold in Japan (where it was sold new) until 1993 so when it came to NZ it was registered here as a 1993 because that was when it was first registered.
Regards,
K-BIKE