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  1. jimmbo

    Gas - Oil Mixture on old Evinrudes outboards

    When poured in, it will settle on the Bottom
  2. jimmbo

    Mercury 85HP Thunderbolt Ignition Series??? Whats missing??

    The 72 80hp and the 73 85hp are very different engines. They might have the same Bore and Stroke, but the Induction System is much different. Carb Calibrations would be likely different between the 4 and the 6s The 1978 and later 80hp engines are not the same as the 72 and earlier 80hp This...
  3. jimmbo

    Am I under proped?

    Early in the Season, when the Air is Cooler and Drier, an engine will make more Power than during the Hotter and more Humid Days of Summer. so in July the Rpms may very well be at 4800
  4. jimmbo

    1976 135HP Evinrude No gas going to spark plugs/cylinder

    If it has spark,(a spark at a Plug, in open Air, really means Nothing). Can the Spark jump a 3/8" Gap? Is there fuel in the Carb Bowls? if not, there could be a blockage, or gummed up Inlet Valves in the Carbs I hope you are not trying to start/run it without a supply of Water for the Water...
  5. jimmbo

    Am I under proped?

    Props may state the same Diameter and Pitch, but often are like Apples and Oranges. 200rpm over the WOT range, isn't instant Death for the Engine, but it might affect overall Longevity, though less than Over-propping would
  6. jimmbo

    How to choose an old 2-stroke 150/175 Merc

    Butchery, that is all it is. I doubt it even adds 1/10 mph
  7. jimmbo

    How to choose an old 2-stroke 150/175 Merc

    So the Exhaust now also comes out the Water Discharge Drains just above the AV Plate, which will also dump more water into the lower Exhaust Passage. Backyard Butchery
  8. jimmbo

    How to choose an old 2-stroke 150/175 Merc

    Nitrous would increase the Power(Torque) at any Rpm that is utilized at. But at Rpms above the Spec Range, the Port Timing will still restrict Induction, and the Power will still be Lower than what the Peak would be. Likely Melt the powerhead too...
  9. jimmbo

    Help Getting Boat on EZLoader Trailer

    Perhaps some Air in the Trim System. Check the Service Manual regarding Bleeding. On some, but not all, designs, just running the Pump after the Unit is at the Stops, was the way to purge Air
  10. jimmbo

    How to choose an old 2-stroke 150/175 Merc

    Spinning it faster than the Recommended WOT Rpm Range, will result is a Horsepower Drop, unless the Port Timing, Induction and Exhaust are modified.
  11. jimmbo

    Help Getting Boat on EZLoader Trailer

    I can't speak for what Racer does, but I drive my Boat on to the Bunk Trailer, yrs ago when I had the Roller Trailer, I always used the Winch. Backing in too deep and you will have many problems trying to get the Boat Centered on the Trailer. I used to sit at the Launch just for the...
  12. jimmbo

    Help Getting Boat on EZLoader Trailer

    This how far/deep I usually back my Bunk EZLoader in, but I have loaded it with the Trailer about 4 feet forward My Roller EZLoader never had to go in any further than this
  13. jimmbo

    How to choose an old 2-stroke 150/175 Merc

    looks like a 20" to me The Serial # should be on a disk, that looks sort of like Frost Plug on the Engine Block. Looks like a late 80s/early 90s
  14. jimmbo

    A prop question (enertia or other versus older props)

    I have been running an Enertia since 2006. It is a very good Prop, and it has a Tenacious Grip on the Water. Your Boat will likely ride Higher out of the Water, the entire Boat, not just the Bow. However a 15X15 is probably not enough Pitch. Your old AL Prop, was it cupped? The SS you put on...
  15. jimmbo

    383535 vs 311932

    While the 18/20 hp shared the same displacement as the 25 in 69, they had different Pistons, Crankshafts, Carb, and as you know Cylinder Heads, The 25 Head has a smaller Combustion Chamber, to restore the Compression that the 25's Pistons reduced. Putting a 20hp Head on a 25 will really drop the...
  16. jimmbo

    No sparking v4

    1966 - 1968? 1971, 1972? 1978 - 1980? These are just some of the years that there was a 100hp, and all are different.
  17. jimmbo

    Prop Help

    85+% of Boaters have No Clue about Rake and Cup, what they are or what they do.
  18. jimmbo

    Gas - Oil Mixture on old Evinrudes outboards

    Yes, I have watched People meticulously measure the Proper amount of oil, fill the tank, pour the Oil in, put the Cap on, start the Motor and go... Contrary to what the Oil Makers say about easy mixing, it isn't self mixing.
  19. jimmbo

    How to choose an old 2-stroke 150/175 Merc

    That was an interesting Read about the Development of the Merc V6. I remember reading how they made a V12, by placing 2 V6s kind of facing each other
  20. jimmbo

    Gas - Oil Mixture on old Evinrudes outboards

    If the Bearings are Well Lubed at the Specified Gas-Oil Ratio, more Oil doesn't make them Run Smoother. 16:1 was used prior to the Mid 50s. Some Engines, like the British Seagull, used a 12:1 or a 10:1, even in the 70s. They were Great for keep Mosquitos at bey Most engines from the 70s can...
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