What amp should your alternater be when running a msd on a single engine application......I ask because my housing on my alternator was cracked and i think it was giving a weak charge to the batteries and in turn not firing my msd properly......If ya have had similar problems post your expierince please..........65amp is what a aftermarket marine alternator is and i dont think that is enough....

Mike on our twin engine Skater we only ran one 65 amp alternater, as long as we had 12.5 to 13.5 volts the trim pumps and MSD worked great, I think volts are the most important to make the MSD work.