Really stupid noob tach question

[Lang]

I put a /5 speedo/tach on the /2 conversion I just finished building. This is my first BMW and the tach has me a little perplexed. Where is 1000 rpm? There are tick marks at increments of 500 rpms and 2 tick marks before 2000 rpm. Those marks I would think would be 0 rpm and 500 rpm but that' can't be right since the next tick is 2000.

So which one is 1000rpm? Thanks!

[Bamboo812]

The first mark is 1000 rpm, which makes setting the idle on a /5 at the factory recommended 800 rpm a bit of a guess. Later bikes used higher idle speeds.

[Kurt in S.A.]

Interesting! Never been around a /5 before to notice this. My guess is that the two marks below "2" are 1500 and 1000. There's typically no reason to need to read RPMs much below 1000 on an Airhead...idle is 1000 to 1100 IMO. Possibly during carb synching, but it can be done with out a tach. I'll be interesting to hear from /5 owners.

Kurt in S.A.

[Lang]

Much thanks - seems an odd way to have it set up but I understand and it is the only way the numbers make sense.

[Texer]

I just think it's wonderful that you have a /5 Motometer that actually works