Hi everyone I am Andrew and I have a dt 125 re 2005 which feels really flat. I have just put a new piston and rings in, done the crank seals etc. It ticks over smooth and drives through all the gears but is really lagging in power in ever gear. I have pinned the power valve open half way to try that but it is still flat. You open it up we're it starts to get going but just bottoms out on the revs change gear bottoms out again. When you put full throttle out and max it to the top it starts to miss like it's not sparking right or not getting enough fuel to give it that extra power. does not have that power valve type feeling on it. I can ride it about round the doors but it is so flat. Only Doing about 40 mph top end

Have you done any other work to the bike?

How fresh is the plug? Is the air filter clean? Is the fuel fresh?

Was the power valve working before?

Done a compression test only reading 90psi. Just had brand new head, piston and rings. I'm I missing something. Both rings are the same arnt they on a 2 stroke.