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350 Mag Merc feels flat

"I posted and subsequently cur

"I posted and subsequently cured the misfire on my Rinker, I also mentioned my gear selection/throttle problem which is under investigation. I spent 2 hours on the water today and have noticed that the boat is really down on power, I went out on a friends SeaRay last night (same engine) and it was responsive and smooth. Just to remind you, the boat has been laid up for 6 years and although serviced and winterised, it wasn't wet run. We've replaced the entire ignition system, stripped and cleaned the carb, replaced the fuel filter (twice!)and have put in a lot of labour to get the boat on the water. At certain RPM, there is a vibration, as if something is out of balance, i can't get any more than 3500 rpm so it struggles to get on the plane with just me on board and feels like it's dragging it's arse (ass to you folks over the pond!) I had 3 people in it today and it would not plane and just bogged down. When i've had it up and planing at speed all seems well, oil press is 3 bar (30c day!) and water 160f but put it in to a turn and it will fall off the plane and struggle to get going again, could this be a prop issue??? I know I've asked for your advice on a few things now but I am a novice and any tips would really be appreciated!

Mark"
 
"Ayuh,.....

Here is a copy


"Ayuh,.....

Here is a copy of Don's list.
Engine Won't Reach Operating RPM. Check

Fuel condition. Type and Octane possibly old fuel
Propeller pitch or diameter, damaged blades
Restricted fuel pickup tube or anti siphon valve Fuel System Test
Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
Marine growth on hull and outdrive
Wrong gear ratio in outdrive
Restricted carburetor air intake (clogged flame arrestor)
Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
Poor cylinder compression Compression Test
Carburetor defective, or wrong type.
Fuel pump pressure and vacuum
Boat overloaded, improperly loaded, or improperly trimmed.
Engine Overheating
Engine timing and ignition system operation
Remote control cables and linkage for proper travel to open throttle plates fully."
 
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