80 psi with the decomp operating is about the minimum at which the engine will start and run - you likely have problems. Have you added a teaspoon of oil to the cylinder to see if compression goes up? If it does, this is an indicator of worn rings or cylinder wall.
'01 660 Raptor, Burgard +2+1 arms, YFZ Shocks, LSR anti-vibe, CTR pipe, jetted, K&N
'01 Polaris Scrambler 400, K&N
'02 Honda 400ex, Big Gun pipe, jetted, K&N, Lonestar +2 A-arms, Lonestar anti-vibe
'02 Honda 400ex, DiamondJ +3 A-arm widener, Lonestar anti-vibe