We heard many times about the difference of power between an 84-85 K100 model and an 86 but I could not find any difference for the cam shafts on my parts CD. The reason is that my catalog is EU only and the cam shafts modification is only valid for the US bikes.

Here is a copy of a post by Themason and found on the K-brick forum:

"Early US 49-State (all states but California) K-100's came with 284 degree cams. Late in the 1985 model year a US 50-State bike was developed with a shorter duration 240 degree cams. this latest model had a hose to route fuel tank vapors into the crank case instead of venting these to the atmosphere, The 50-State bike has 6-7 less horsepower, most noticeable in their lack of top end rush compared to a 49-State bike. I believe all the EU bikes came with the 284 degree cams, but I could be wrong..."

I went online to the Max BMW parts fiche and found the following:



According to the parts fiche, the second generation of cam shafts has a 256 degrees cams in stead of 240 as stated in Themason's post.

We finally got the answer!

My K100 (US model) was built in September 1984. Happy 25th birthday :geek:

If you want to know when your bike was built, check the following page: K100 serial numbers

Bert

very interesting - thank yo Bert for clarifying this.
I keep reading "themasoms" posts - he seems extremely knowldgable and capable - far beyond what I understand at times yet always interesting .