I need to know the exact base timing for these rebuilt 11:0 Chevy Mercruiser engines in my 74' Concord boat. Currently they are set at 10° btdc. I removed the Thunderbolt ignitions, and replaced them with DUI mechanical advance marine distributors. Thanks
GM marine grade from Marine Parts Source in Whitehouse, TN.
GM marine grade from Marine Parts Source located in Whitehouse, TN. Thanks a bunch for the schematic my friend 😉
Thanks for the info...only the port engine tach is operational...the synch is located on the flybridge, and is disconnected...any additional info would by greatly appreciated 😉
I recently retrofitted my 74 mercruiser 427 engines with marine GM high energy ignition systems. I completely gutted the Thunderbolt ignitions. The port engine tach reads approx. double the actual rpms. I havent even connected the gray tach wire on either engine so where is this signal coming...
I retrofitted my 427 mercs with GM hei ignitions....port motor still shows approx. double rpm on tach...gray tach wire on hei isnt even connected...where is this seemingly spurious signal coming from ?
