Update: When I add a bit of oil into the cylinders the psi jumps up to over 170psi. From what I understand this typically means worn rings or cylinder walls. But as described below the rings are brand new and the cylinders were honed. What else could this mean?
Compression is 85 psi on both sides. That's exactly half of the 170psi that it should have brand new. Compression tested with the throttle wide open, choke off and both spark plugs removed.
I replaced all of the piston rings and honed the cylinder walls. The pistons are standard pistons and the engine has not been overbored as far as I know. The rings are NOS honda standard rings. (I used this hone: https://www.amazon.com/gp/product/B00A4AI972) Replaced the cam chain. Replaced all gaskets including head gasket of course. Lapped the valves and replaced the valve stem seals. I level sanded the head with 220 grit so that it was dead flat for a good head gasket seal. I torqued all of the head bolts in the correct sequence down to 16 foot pounds torque.
When installing the rings I spaced the ring gaps at equal distances apart as called for. I also made sure that the rings were all installed with the right surface facing up.
It seems conspicuous that both cylinders are basically exactly half the proper psi spec. Maybe doesn't mean anything but is there something particular I may have done wrong that would give this result? What do you think?
Compression is 85 psi on both sides. That's exactly half of the 170psi that it should have brand new. Compression tested with the throttle wide open, choke off and both spark plugs removed.
I replaced all of the piston rings and honed the cylinder walls. The pistons are standard pistons and the engine has not been overbored as far as I know. The rings are NOS honda standard rings. (I used this hone: https://www.amazon.com/gp/product/B00A4AI972) Replaced the cam chain. Replaced all gaskets including head gasket of course. Lapped the valves and replaced the valve stem seals. I level sanded the head with 220 grit so that it was dead flat for a good head gasket seal. I torqued all of the head bolts in the correct sequence down to 16 foot pounds torque.
When installing the rings I spaced the ring gaps at equal distances apart as called for. I also made sure that the rings were all installed with the right surface facing up.
It seems conspicuous that both cylinders are basically exactly half the proper psi spec. Maybe doesn't mean anything but is there something particular I may have done wrong that would give this result? What do you think?