the story: redid the motor, new bearings, mains, rings, cleaned off carbon from head, replaced 2nd hand block, original block had very bad piston slap cause by gungeon pins. swing but nothing there is fuel there is spark car swings freely like no compression, but cranked the motor for compression before fitting plug leads etc.. crank sensor connected and speed sensor connected. something im overlooking? plugs are dry, no oil or fuel.. anyway to check comp without removing the head or diy with minimal tools? thanks.