Have a 87 5.7L 260 hp mercruiser alpha 1 with t-bolt ignition. I have been through the Seloc manual and have followed the troubleshooting. Not alot of info avail. Ultamatly it suggested to replace the sensor inside the dist. I have also replaced the cap, rotor and coil. When I place coil wire 1/4' from ground spark is yellow not blue. even weaker at the plugs. When I crank the engine it almost starts right away. Have tried starting fluid with same results, assuming it's not fuel delivery. Any suggestions