Mariner 150 no power

[Greenhead2012]

We are having an issue with a 1992 692 Ranger Fisherman with 1992 Mariner 150 Magnum 3. It has a five blade mercury high 5 ss prop with 20 pitch. We checked out the motor and changed everything from plugs to fuel filters. All 6 cyl are 108-110 on compression tester. With two guys, 4 batteries and 9.9 kicker it takes atleast a minute to get above 10mph. 0nce it hits 15mph (if wind is in ur face u wont get on plane) it will plane out and trimmed up runs 38 mph at 4000 rpm tops. We were on Erie 2 weeks ago and coming back into the wind/waves we couldn't get over 10 mph and couldn't get on plane with 3 guys. We were thinking too big of a prop but do you guys agree or maybe carb problem? Manual says motor should be running at 5-5600 rpms. We are stumped as far as our mechanical skills go.

 

[aussieflash]

Re: Mariner 150 no power

G'day,
First thing is to check for strong spark on all six.Then I would check for dirty fuel lines and pickups etc.After running pull al plugs and report on condition...spotless,brown or black.I would start there and if all checks out I'd pull carbs for a full rebuild/clean.
The list goes on and on......Stator.....timing...............