1991 K100 rs - need to lube splines?

I just bought a 1991 k100 rs which I am getting running for my son. I know some of the older bmw bikes need the splines lubed often. Is this one that needs it? The manual suggests this may not need it much. It has 28,000 miles and has been sitting for a while (8 years). Thank you for your thoughts!

It is generally recommended to lube the splines on all BMW K bikes that have a dry clutch at least every 40k miles. I would definately take it apart to lube the splines and inspect everything. I used the spline lube sold by Beemerboneyard as recommended by many experts and I couldn't be happier.

Thank you!

And the rear splines at least every other tire change.

If I'm mis-stating the consensus of opinion on servicing the TWO DIFFERENT SPLINES, please correct me:
1. Clutch splines on most BMW's (not just K-bikes) should be cleaned and regreased every 40K., a fairly major job. If you have difficulty downshifting, that is a clear sign you should do the job NOW before expensive damage occurs.
2. 2-valve K-bikes (I believe through 1990) should indeed have the final drive cleaned and greased every other rear tire change or 15-20K.
3. 4-valve K-bikes (1991 on) have a Paralever suspension that does not cause nearly as much wear on on the final drive and the service interval can be considerably longer. (How much longer I don't know.)

Since the OP's bike has been sitting for 8 years, it probably would be a good idea to service the rear splines - not such a big deal. My bike (1992 K100RS) also must have sat for a number of years as it only had about 12K when I bought it - and judging by the condition of the bike, the mileage was believable. Now it has 22K, doubt the clutch splines have ever been touched, and it still downshifts perfectly.

BMW's maintenance schedule didn't require the pinion splines of Monolever (1983 - 1989 ) K bikes to be lubed more frequently than the other two splines, but experience shows these splines were the wear point and popping the final drive off a Monolever bike takes minutes to do, so it became de-rigueur to lube them more frequently. Some say every tire change, I did mine at every 10K service. either or is fine.
The u-joint splines and clutch splines could last 40-50 K miles before needing to be lubed. I used to go 50K with no problems noted.

Disassembling a Paralever and reassembling it correctly, meaning getting the correct preload on the rear needle bearings, takes a lot of time and effort. You are not going to pop a final drive off every 10K miles in the fifteen minutes one could do it on a Monolever bike. On Paralever bikes perform the spline lube every 40K miles cleaning and lubricating the drive shaft and clutch splines in one long and ugly day.

I agree that clutch splines should be lubed at a 40K interval.

I agree that monolever rear driveshaft splines need to be lubed every 2nd tire, and every tire if you are getting over 10K a tire.

The paralever driveshafts have clipped splines at front and back, and the intermediate spline is very robust. Lube them when you do the clutch splines and they will outlast the universal joints.