1986 MerCruiser 305 hesitating above 3300 RPMs

[Justinx1997]

Hello everyone, long time reader, first time poster. I recently purchased a 23' 1986 Mach 1 Condor, which has a 305 Merc in it with Alpha 1 outdrive, Thunderbolt IV ignition, and 4bbl carb.

Here is my issue: Boat runs fine up until approximately 3200-3300 RPMs. To go beyond that, i have to go WOT, the engine bogs down to the point where it feels as though it is going to stall, and then a few moments later it will kick back in and run as it should, reaching its maximum RPM (4500-4600).

Ive read other threads where people were having similar problems, and people's inline fuel filter was clogged where the fuel line goes into the carb. I checked that and it was clean with no debris. Where should I look next? Like I said, once the boat gets past that hesitation/bog, it runs fine at WOT, and runs fine up until approx 3200 RPM. Could this issue be with my water separator? Any and all help is much appreciated.

 

[alldodge]

Howdy

Sounds like your not getting enough fuel as the secondaries are opening. Your fuel bowl may not have enough fuel in it, so check the float level. and the metering rods and channels are clear. What do your plugs look like?

 

[Chigwalla]

Whenever you have an issue that even hints at fuel starvation, check the water separator first.
If you have one, run the engine on a day tank with fresh gas to eliminate a restriction in the boat's fuel system.

 

[Justinx1997]

Thanks for the replies, guys. Replacing my water separator tomorrow and will then test. If the issue persists, then I will pull the plugs and see what they look like, and see what the carb is looking like inside.

 

[Bondo]

Replacing my water separator tomorrow and will then test. If the issue persists, then I will pull the plugs and see what they look like, and see what the carb is looking like inside.

Ayuh,.... Welcome Aboard,.... When ya pull the fuel filter, dump it's Contents into a clear jug, 'n Look for water, 'n crud,.....

When ya check the spark plugs,.... Do a Compression test on the motor,....