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78 Mercury 80HP/800 top end power help

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  • 78 Mercury 80HP/800 top end power help

    I have a 1978 Mercury 800/80 hp SN range 4831999 and up. I have had multiple issues in trying to get this motor up and running again. I put it in the shop last year to get the kinks worked out. The mechanic told me I had the wrong trigger and he rebuilt the carbs. All was fine and running well when I got it back, and now I have limited RPM and can only run at about 10 mph vs. the 45 WOT I had before. I had multiple fire on all cylinders and through dumb luck put the original switch box back on corrected the firing issue. I have adjusted the timing (with a timing light) and set the pick up to 4 BTDC and the MAX Spark at 27. I have installed clear tubing at the carbs to check for any air leaks in the system and all seems to be fine. All wire connections are secure. The new components on the motor are as follows:

    Switch Box
    old: 332-5772A1 (currently installed) new: 114-5772
    Trigger
    134-6454 (installed) 134-6452 (recommended by iboats)
    Rectifier
    154-6770 (installed) 194-5279 (alternate part)
    Stator
    174-5454K1

    I have purchased a DVA adapter PN: 511-9773 to use with my Actron CP7677 auto trouble shooter, but I cannot get a smooth steady reading. I have read through the CDI trouble shooting guide and it would be helpful if I knew exactly how to set up the DVA for use. I still want to check and make sure I don't have any bad coil packs. The compression average for the motor is 136 psi, plus or minus 2 psi. What am I missing or over looking? Any help would be appreciated.

  • #2
    Most multimeters you set on DC Volts and DVA plugs into positive and negitive meter jacks, then read voltage as per manual.
    Regards
    Boats.net
    Mercury Outboard Parts
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    • #3
      yeah, i got that much. do i disconnect the rectifier then test? I cannot seem to get a steady reading anywhere I try, it jumps around very rapidly

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