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  1. J

    Cobra sucking air-

    1988 5.7 liter omc, cobra leg. After putting on a clear hose from oil cooler to thermostat housing, the hose runs pretty clear (very few bubbles at idle) but then really has air in the hose at 1/2 throttle and WOT and it runs hot. What is the most likely cause? I am taking the outdrive off...
  2. J

    UPDATE -OMC runnin' hot-

    See prior thread for history- last night I took of the oil cooler to check to see if it is plugged- blew it out and re-installed. nothing- still running hot at WOT- for update- replaced: IMPELLER, RISERS, THERMOSTAT,- couple questions- when I first wet the boat, there was a lot of carbon...
  3. J

    omc 5.7 running hot

    I have a 1988 trophy flybridge with a omc 5.7 liter (4 valve per liter) and a cobra outdrive. Just acquired the boat. It runs HOT over 220 degrees when wide open. When you let off and go to 1/2 throttle, temp comes down until 170-180 still HOT. It runs 140-150 at idle, 170 degrees at 1/2...
  4. J

    4.3 Cobra leg on a 3.0

    Second post regarding the 4.3 cobra leg I have. I asked a similar question on February 1st only it was using the 4.3 on a 5.0. Now I want to know if the 4.3 (gear ratio 21:19) can work on a 3.0. The person states the year of the boat is 1989 so the gear ratio is either 21:18 (pre 1989) or...
  5. J

    Cobra 4.3 compatible for 5.0 engine?

    I have a 1986 rebuilt 4.3 Cobra with a gear ration of 21:19. Can this be used with a OMC 5.0? I know it will bolt on, but should the pitch of the prop be changed, and what pitch do you recommend. Thanks
  6. J

    Cobra gear ratio

    First time to post- I will try to do it right. I bought a couple of outdrives to rebuild for spares, I was told the both are from V-8's. One says 5.7L on the plate and it has 21:16 gears. No problem. The other I have questions about is what I believe to be a 1987 Cobra outdrive- Model #...
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