GeorgioP07
Cadet
- Joined
- Sep 15, 2025
- Messages
- 6
Hello,
My Family and I bought this 2012 Bayliner 185 with Mercruiser 3.0L in later Summer 2024, ran it a few times, did a tune up, new plugs, wires, cap, rotor, water pump impeller, anodes, thermostat etc.. no problems, and winterized it well. Starting in 2025, w/fresh pump gas, -we noticed that the tach won't reach over 2900 RPM's on the lake at wide open throttle. It runs fine in the garage with muffs, and reaches over 4500 RPM's - no problem as long is it's not in the lake. So I went down this rabbit hole, new fuel pump, rebuilt the TKS carb to specs in service manual, got a timing light, checked timing and was dead on, bought the special slotted screw and fuel/air mixture screw then adjusted (she preferred 4 turns out when warm), re-gapped plugs, tightened throttle cable, oil level not over, but full on dipstick.
I didn't replace condenser, since engine starts well, runs well enough (has a slight stutter from 2400 RPM- 2600RPM), but smooths out. On the lake at wide open throttle, it only climbs to a max of 2900 RPM, and goes no more which equates to going 15MPH at best. Oil pressure at 65psi at wide open throttle. Temp at 180F or so. In garage, at wide open throttle, it's fine, over 5K RPM's on tach with no load on prop. Engine wants to idle at 900RPM, not so much at 750RPM, like the manual states, or a bit of shaking takes place.
Using same propeller as last year, with it went 35+ MPH on the lake. It is a 3-Blade MerCruiser 135-300HP: 14 1/4 x 21 with hub kit. Boat not overloaded, and no growth on hull, it's on trailer 98% of the time, no drag on hull. I've not adjusted the shift cables yet, but I am leaning from lack of speed on the lake not being an engine issue to more of a drive issue, or power loss from engine to prop. Kids want to go fast on the tube and Dad is letting them down.. Please help.
My Family and I bought this 2012 Bayliner 185 with Mercruiser 3.0L in later Summer 2024, ran it a few times, did a tune up, new plugs, wires, cap, rotor, water pump impeller, anodes, thermostat etc.. no problems, and winterized it well. Starting in 2025, w/fresh pump gas, -we noticed that the tach won't reach over 2900 RPM's on the lake at wide open throttle. It runs fine in the garage with muffs, and reaches over 4500 RPM's - no problem as long is it's not in the lake. So I went down this rabbit hole, new fuel pump, rebuilt the TKS carb to specs in service manual, got a timing light, checked timing and was dead on, bought the special slotted screw and fuel/air mixture screw then adjusted (she preferred 4 turns out when warm), re-gapped plugs, tightened throttle cable, oil level not over, but full on dipstick.
I didn't replace condenser, since engine starts well, runs well enough (has a slight stutter from 2400 RPM- 2600RPM), but smooths out. On the lake at wide open throttle, it only climbs to a max of 2900 RPM, and goes no more which equates to going 15MPH at best. Oil pressure at 65psi at wide open throttle. Temp at 180F or so. In garage, at wide open throttle, it's fine, over 5K RPM's on tach with no load on prop. Engine wants to idle at 900RPM, not so much at 750RPM, like the manual states, or a bit of shaking takes place.
Using same propeller as last year, with it went 35+ MPH on the lake. It is a 3-Blade MerCruiser 135-300HP: 14 1/4 x 21 with hub kit. Boat not overloaded, and no growth on hull, it's on trailer 98% of the time, no drag on hull. I've not adjusted the shift cables yet, but I am leaning from lack of speed on the lake not being an engine issue to more of a drive issue, or power loss from engine to prop. Kids want to go fast on the tube and Dad is letting them down.. Please help.
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