George, Roger, thank you very much for always following along.
Today was a perfect day in the R&D department.
Overall run time in the records now 193 Minutes.
Jeff (rustcollector) has given another recommendation to decrease the exhaust duration by adjustment.
Roger has mentioned earlier already, that valve lash can get an influence to the duration too.
Exactly this was done now.
I have increased valve lash of the exhaust to 0,2 to 0,25 mm.
This does results in decreased duration from 260° to 245° crank shaft, exactly what should be archived.
The opening of the exhaust does start now with 50° before BDC and there is a very small remaining overlap.
See picture #1 below.
That is my final timing now.
The engine is running in my understanding very nice with this timing.
Lowest measured rev/min less than 500.
Some time ago Jeff (rustcollector) has mentioned also, that the Chinese 3 mm carb with a slightly modification by an 0-ring internaly, should feed this engine very well also.
So far my 4 mm DIY carb was best running nearly closed so that was another reason to try this 3 mm carb again.
In this video the final above mentioned timing and the 3 mm carb.
[youtube1]https://youtu.be/9gVyiOx_FCk[/youtube1]
For me the result is absolutely perfect.
My CNC mill has made some new modified exhaust cams yesterday, but they are collected by a ty-rap now and will find its place, together with the other remaining parts of this build, under the bench.
So finally thank you very much for all here giving the useful support during my journey and of course for watching this build quietly.
A very special thanks to Jeff (rustcollector), he has been always right with his suggestions
A Plexiglas cover is ordered and some space, very close to the Snow engine is prepared for the storage.