DanP off here has bought GurnE's shell weve reshelled his saff into it, weve got fuel and spark but it wont fire, took the plugs out and the cylinders are swimming so atm left plugs out for it to evaporate

anyone got any ideas on what this could be

 

timings out, no compression or faulty sensor. was the engine running ok before it was fitted into this shell or has it been apart