1974 165hp Merc 235 Inline 6<br /><br />This thing has no tach. Familiar with the 350 in my van, but how does it work with the old points ignition, and do I just go to the parts store and ask for one for a 6 cyl, or does inline make a diff.<br /><br />Thanks 
<br /><br />New to me boat, would like to know how the engine is doing rather than just listen and guess.
<br /><br />New to me boat, would like to know how the engine is doing rather than just listen and guess.