ORIGINAL: Henning

I used to run 56 cm from exhaust flange on the engine to first baffle in the pipe for the Hatori
# 700. Using 15 % nitro and APC 15x8 prop. Static RPM around 9500. On a real hot summer day you might run 60 cm.

The OS 91FX runs better with an extra head shim and the OS # glow plug.


Hope this helps.
Henning