Thread: Johnson "70mod"

  1. #281
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    your dead right there Jeff
    and it is not far out when seeing the so called fuel frugal E-tecs at full throttle too.

    with the mods done on this motor the fuel consumption as still stayed around the same, this being due to letting the motor breath a bit better and not going to mad
    on the modifications. great all round modifications and some pretty extreme results with speed. !!!

    will see how it goes when the bigger carbs go on , should be miles better at pull away and mid range, with just a small amount on top end.
    that is what I found when going up to the big carbs.

  2. #282
    Team Member hupiveneilija's Avatar
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    Update:
    Cooling is now solved. Made dumpvalve for incoming water, changing spring can adjust max pressure. I dont have that thermoelement in place in that plastic surrounding yet so idle temp is ~40*c and it rises to 60*c on wot. Can make it higher or lower now and it stays steady.

    Also changed mainjets from 56to52 and middle jet from 32to36, goes better downlow and little snappier on top.

    One very irritating feature is when make fullthrottle start and trim is all the way neg, bow goes so high that fluid level on bowls goes here'n'there and it stalls couple times before goes. But there is attleast one solution for that, nice and smooth takeoff!
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  3. #283
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    What engine is that ?
    It's got flywheel from oval port, cylinder head from bridge port and exhaust cover tell tale pipe ?
    Tell tale should be from top.
    Idle temp should be higher than full throttle.
    You obviously still have water problem.
    With proper omc modified thermostat and cover it would work better.

    To stop fuel bowl problem make baffles that go in the bowls like on v4 race engines.

  4. #284
    Team Member hupiveneilija's Avatar
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    Its 1992 mix'n'match from the factory.
    Hey dont worry, everything is in order😉.

    Popquiz: sst60 thermostat degrees?

  5. #285
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    Omc SST60 thermostat temp 143 f deg = 60c. . this seems to be same running temp for all omc outboards from 5hp to 225hp.

  6. #286
    Team Member hupiveneilija's Avatar
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    Oh, why the parts list doesnt include one in that engine?

  7. #287
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    there is a few missing parts from the catalogue. thermostat , steering arm nut.
    probably loads of parts that are just sundry items

  8. #288
    Team Member hupiveneilija's Avatar
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    Today 57.5kn.
    https://youtu.be/ad5E8urDmGA
    56kn 2 person. Both with 3blade. Slip is little on the high side, have to use tools on the prop.
    Prop is better on holding rear in the water than ever, even my wife said it feels real steady and have good "traction". And she was first time in the boat.😂😂

  9. #289
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    that dont sound like its revving over 7,000 rpm. looks nice handling
    when you put video on 29. heinäkuuta 2017 the motor was revving much higher and boat looked faster.

    in the video above what was the rpm, speed and prop.

  10. #290
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    57,5kn, ~7800rpm prop was srx, it stays really planted on the rearend.
    Sounds like stock😂😂

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