Thank you for your answers. Maybe now that the temps are around 10-15 C i'm lean, but i was told by others (my experience in trials is limited to this bike) that this is the problem with trials 2T, if you use it full throttle, like when climbing long hills or traveling woods roads, it will overheat. They said you can't jet it to be ok for both slow riding and fast let's say enduro style riding.
Now i have fitted a catch bottle but didn't have the time to test it, but i'm sure it will work because on my enduro bike it works beautiful.
The jetting is 27.5 pilot, stock main, and needle up maximum, still pinging at the top of a hill and if i insist then i can hear the water boiling in the cylinder, the higher the gear the worse is the pinging. The piston top it's almost clean, the exhaust it's clean, the muffler redone, the advance it's adjusted at 2.2mm as recommended.
When cold it has full compression and i must use all my weight to start it, but when it's hot i can start it easier, i don't know if it's normal.
What it's your advice, should i buy i 28PWK Keihin, then i could finally use it as it should be a bike, not overheating when going fast for minutes?