thanks for replies ))
Tom
nozzles are made from 24mm hexagon stock, M20x1.5 thread, cannot remember, why i made taper on the end - probably for aesthetic reasons
sprocket is just cover for ash removal port - it was thick enough to cut thread into.
another item from scrap pile ))
Steve
yep, it is not a failure in my opinion, just replacing a consumable - let us see how long that brake rotor will hold.
engine is not tarred - everything is fine.
Jan - there is an old thread where i was asking for advice while building it.
forum members did help significantly and allowed me to avoid some beginner’s mistakes
here is the link