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[Mege66]

He‘re two videos of my overhauled and refurbished Topaz.
Maiden voyage: [size=78%]https://www.youtube.com/watch?v=TuUYUWHkAOw[/size]
Second run after some tweaking: [/size][size=78%]https://www.youtube.com/watch?v=LyreRAR5rD8[/size]

[derekwarner]

Yes congratulations Mege66, she steams so elegantly in that second video


Derek

[Mege66]

Thanks Derek


I’ve spent some time with bathtub tests until I was able to control the Gemini RPM range between 300 and some 1800 under load and also linearized the regulator stick as much as possible. The Gemini is now neatly following the stick movement and has become very controlable on the regulator.


The only minor issue is that the engine occasionally needs a throttle ‚kick‘ to start running. I think that the O-rings have become hard over the past 30 years.


If anybody happens to have the O-ring dimension at hand I‘d be grateful if the could share this information.

[rhavrane]

Bonjour Mege66,

The only minor issue is that the engine occasionally needs a throttle ‚kick‘ to start running. I think that the O-rings have become hard over the past 30 years.

Based on my experience on new steam machines which show the same behaviour, I have another hypothesis, when the speed drops, or even stops, the machine cools down and if like me you are sailing at an operating pressure of around 30 PSI, the saturated steam condenses and it is necessary to give a little more steam to expel the condensate that formed.

[Mege66]

Hmmm, that’s an interesting thought Raphael.


The problem is that it happens always, even after very short stops of just a secondor two, like for example for reversing.
But condensation won‘t help the restarting process for sure.

[rhavrane]

Bonjour,
To my opinion, there is also possibly another possibility, small poor distribution timing. The smaller my machines are, the more I have to face difficulties in finding the right setting.
In theory, the valve must begin to reveal the steam inlet and the eccentric must be at 90°.
This happens at a few degrees and this can be enough to create a false dead center despite the fact that the second cylinder is supposed to still be moving escept if you close the stem when you reverse.
It happens on many of my machines and I have solved this problem by not stopping any more steam when I reverse, I just slow down.
 

[1967Brutus]

It happens on many of my machines and I have solved this problem by not stopping any more steam when I reverse, I just slow down.

Oops, I was completely wrong here, since OP's engine runs in one direction and the boat reverss by means of a reversing gearbox.

My bad!