A few months back I asked some questions regarding our 1979 85HP V4 Johson, which worked (needed some work!) but was not all that reliable and a bit underpowered. For those who remembered, I even asked if it's practical at all to convert from OB to I/O.<br /><br />And then, just a month before the boating season starts again, in a single day we bump into a great deal, act quickly and snatch the deal away before someone else can. A 1988 Merc 150HP V6 Black Max. A 2 stroke is a 2 stroke, and a 4 would cost SO much more we'd not break for years. <br /><br />It's in excellent condition, including controls, gauges, manuals, and a quicksilver SS 21" prop. A friend has got spare Merc props 17", 19" and 21" so we'll be able to find the best match. Compression was perfect, had a guru look at it and he loved the thing. GREAT price too 
<br /><br />The manual is for slightly newer models, so while most applies, I don't know if this model actually gives 40amps charging power, does anyone know?<br /><br />The Johson 85 (flywheel horses of course) would push the boat (20') just shy of 25 knots with a 17" aluminium prop, don't know the RPM. What could be expected with this combo?<br /><br />Also, what to expect in terms of fuel consumption on a smooth 22 knot cruise, Johson needed pretty much 1 gallon per nautical mile, half of which went straight into the ocean I bet.<br /><br />Any known things to watch out for with this engine?<br /><br />Cheers, and a great forum! <br />Dennis
<br /><br />The manual is for slightly newer models, so while most applies, I don't know if this model actually gives 40amps charging power, does anyone know?<br /><br />The Johson 85 (flywheel horses of course) would push the boat (20') just shy of 25 knots with a 17" aluminium prop, don't know the RPM. What could be expected with this combo?<br /><br />Also, what to expect in terms of fuel consumption on a smooth 22 knot cruise, Johson needed pretty much 1 gallon per nautical mile, half of which went straight into the ocean I bet.<br /><br />Any known things to watch out for with this engine?<br /><br />Cheers, and a great forum! <br />Dennis