Chainsaw Repair

The 3400 run around 125 to 135 psi.
The 3700 will run around 150 to 160 psi
The 4000 is the same as the 3700 they both have two thin rings and the only real difference is in
the bore size as far as compression goes.

I have seen the exception posted where someone got up to 175 psi on the 3700 and 4000 models.