Timing a R27

[sirmanley]

Anyone know how to set the timing on these singles? I know how to do my R60/6. Just don't know if the single is any different.

 

[rpeckham136133]

While not aimed specifically at the R27, Duane Ausherman has a very good technical article about ignition points timing:

http://w6rec.com/duane/bmw/points/index.htm

I have a 50/2 (magneto) and a 60/6 (battery-coil-points), and I suspect that yours has elements of both...

In a nutshell, you will want to access the flywheel timing marks. If they are like my /2 (of the same vintage), you will find OT (which is top dead center), S which is used for static timing, and F which I think is for full advance. Essentially, you set the points to the recommended gap (.04mm I think?) with the points cam at its peak. Then set the flywheel so that the S mark is lined up, and then rotate points plate (the plate on which the entire points unit sits) until the points just break. This sets the static timing, and then you can set it more precisely by using a timing light.

I recommend that you read the article on the /5-type ignition, as this is pretty much what your system is.