2018 EC250 Build up

[Gibnut]

Originally Posted by Jakobi

Bugger me..

Combustion chamber cc's at 21.5cc
250cc piston dome has always been around 6.6cc
Volume of 1mm squish clearance is 3.46cc

Total trapped Volume 21.5 - 6.6 + 3.46 = 18.36
Compression Ratio (18.36 + 249)/18.36 = 14.56

Bit high I think..

If.. it was cut to 1.25mm as requested the ratio would down to 13.93:1 ...which is where my old 2010 was set. Last bike was 13.2:1

So so so.. Where to from here.

Mine went down to TSP twice as well.

Also, after you rip the 5mm thick gasket, check the retainer nut on the PV actuator rod thingy - mine had backed out all the way down the thread.