Ruggerini F25 - digging deeper into this beast

[Anorak_ian]

3800 RPM Ruggerini F25 (Marine outboard version of MD191)... a freaking torque monster...

I have been waiting for one of these to come up for sale so I could rip it apart and see how it ticks, but no joy yet.
Any idea what makes this engine rev so high? My rd210/11 has revved to 3700 so far but more would be welcome. If the F25 revs to 3800 can it be over revved, say 4000rpm?

Also, I have been wondering if the Hatz 1000cc pistons and barrels will fit the rd210/11 for more umph, as it looks like it's the same basic engine design, although same horse power.

[andrewaust]

Without actually seeing the engine I'd hate to commit myself to saying it could rev higher. Usually spring tension can be increased to achieve higher rpm, meaning the centrifugal governor needs more pressure to push against the spring arrangement on the throttle lever. If your stuck for space where the throttle lever moves, a spring of higher weight resistance will probably work.

Just be careful when doing this




A