Sea ray sundeck 240 won’t rev passed 2000rpm

[Easa]

Hi, I have a sea ray sundeck 240 with a mercruiser 350 mag engine that won’t passed 2000 rpm under load, also while cruising at low speed rpm will dropped and engine will eventually die. I already ready replaced a few parts:
Fuel pump
Fuel injectors
Spark plugs
Ignition cap and rotor
Spark plug cables
TPS sensor
I attached a video of my boat even at full throttle it won’t passed 2k rpm

 

[drewm3i]

IAC? MAP sensor?

 

[Easa]

IAC? MAP sensor?

Hi, I already replaced the ICA, do you think getting a new MAP sensor can solve my problem.

 

[Fun Times]

Sometimes when the engine doesn't seem to want to go past a certain RPM like that anywhere from say half to full throttle including no additional boat speed it turns out to be internal engine type issues.

Did this all of a sudden do this or was there some sort of service type job involved at any time and now the boat won't plane?

 

[Easa]

Sometimes when the engine doesn't seem to want to go past a certain RPM like that anywhere from say half to full throttle including no additional boat speed it turns out to be internal engine type issues.

Did this all of a sudden do this or was there some sort of service type job involved at any time and now the boat won't plane?

I just got the boat, so I don’t know if the previous owner did some sort of service. Engine runs smooth when not under load, I already checked engine compression and it’s good. Boat looks like it’s hasn’t being used for a while.

 

[Fun Times]

I just got the boat, so I don’t know if the previous owner did some sort of service. Engine runs smooth when not under load, I already checked engine compression and it’s good. Boat looks like it’s hasn’t being used for a while.

What year engine model are you working with?
Serial number?

If you happen to have an hour and a half of reading time, the following situation may help go over some potentials to consider...Turns out the valves needed adjusted here, http://clubsearay.com/index.php?threads/absolutely-frustrated-with-this-mercruiser-engine.112106/

 

[Easa]

What year engine model are you working with?
Serial number?

If you happen to have an hour and a half of reading time, the following situation may help go over some potentials to consider...Turns out the valves needed adjusted here, http://clubsearay.com/index.php?threads/absolutely-frustrated-with-this-mercruiser-engine.112106/

I don’t have the engine serial number right now, but It’s a 2007 mercruiser 350 mag V8. Engine only have 146 hours. My guess is that this boat was abandoned for years.

 

[dubs283]

How old is the fuel?

 

[alldodge]

I already checked engine compression and it’s good.

What does good mean?

How old is the fuel?

Agree, how old

 

[Easa]

How old is the fuel?

I emptied the fuel tank I added fresh fuel

 

[Easa]

How old is the fuel?

I emptied the fuel tank and added fresh fuel

 

[Easa]

What does good mean?


Agree, how old

Compression test was 115-120 psi on all pistons, I emptied fuel tank and added fresh fuel

 

[Easa]

I was thinking of replacing the ignition coil, do you guys thinks is a good idea?

 

[alldodge]

Compression test was 115-120 psi on all pistons,

If your gauge is accurate then the motor is tired, should be closer to 150.

Check the timing as seen in the pic. Bring number 1 to TDC and then verify distributor location

 

[Easa]

If your gauge is accurate then the motor is tired, should be closer to 150.

Check the timing as seen in the pic. Bring number 1 to TDC and then verify distributor location

View attachment 382841

Thank you! I’ll do another compression test with a different gauge. Engine run smooth just don’t rev passed 2k rpm

 

[alldodge]

While your at it check fuel pressure, it should be 43 psi

 

[Easa]

While your at it check fuel pressure, it should be 43 psi

Fuel pressure at 2k rpm under load is 40psi

 

[Easa]

Fuel pressure at 2k rpm under load is 40psi

I’m thinking of replacing my coil? Do you think it can be the cause of my problem?

 

[alldodge]

I’m thinking of replacing my coil? Do you think it can be the cause of my problem?

No
Very, very rare for a coil to go bad. Folks replace them all the time, wish I had stock in the coil Co I'd be rich

 

[Scott Danforth]

It's never the coil...ever
With only 40psi, your fuel pressure is low

With compression in the 115-120 range, the motor needs a rebuild

If your neutral safety switch is bad, motor won't rev when in gear

Time to start trouble shooting