2007 Mercruiser 5.0 tks 4000 rpm's maximum?

[wpowell323]

Serial # 0W640972 Alpha Drive

I put the boat in earlier this year and figure out it suffered freeze damage. Other than the block leaking it ran perfect, but the oil had a little milk. So I ordered a 5.0 long block and had a friend who is a marine mechanic help me swap everything over. We took the boat to the lake and it will only turn 4000's rpm's. The timing is set at 8* BTDC per the breather and seems to be advancing to 31* at WOT. The boat seems to have good power up to 4000 rpm's, but then it just stops. The fuel is clean, I have spark, even went as far as to change all the wires and cap and rotor. I feel like it is something stupid that I am missing and I am hoping someone on here can help point me in the right direction.

 

[Fun Times]

Are you sure the throttle cable is opening up all the way?
Did you put 2 new OEM gaskets under the carb...One on each side of the adaptor (#16)?
What engine block did you buy? Did it come with a new intake or used your old one?
Are you trimming the drive at speed for better efficiency. Different prop?

 

[alldodge]

Serial # 0W640972 Alpha Drive

I put the boat in earlier this year and figure out it suffered freeze damage. Other than the block leaking it ran perfect, but the oil had a little milk. So I ordered a 5.0 long block and had a friend who is a marine mechanic help me swap everything over. We took the boat to the lake and it will only turn 4000's rpm's. The timing is set at 8* BTDC per the breather and seems to be advancing to 31* at WOT. The boat seems to have good power up to 4000 rpm's, but then it just stops. The fuel is clean, I have spark, even went as far as to change all the wires and cap and rotor. I feel like it is something stupid that I am missing and I am hoping someone on here can help point me in the right direction.

If your using the correct timing procedure, using MR43TLS plugs at .045 gap, then I would put a vacuum gauge on the engine and check if you have 15-18 in Hg at idle

 

[wpowell323]

We set the timing using the est procedure. It is 10* btdc at idle and 31* fully advanced. I am using the ngk plugs mercruiser reccomens, but I did start with the Ac delco before we changed the wires and cap. I am using the intake I had and I never took the carb off the intake. I can check the vacuum tomorrow. If it is off should I look for an intake leak? I have sprayed around with carb cleaner and it seems fine.

 

[alldodge]

We set the timing using the est procedure. It is 10* btdc at idle and 31* fully advanced. I am using the ngk plugs mercruiser reccomens, but I did start with the Ac delco before we changed the wires and cap. I am using the intake I had and I never took the carb off the intake. I can check the vacuum tomorrow. If it is off should I look for an intake leak? I have sprayed around with carb cleaner and it seems fine.

Intake would be the next check. If your vacuum is within range I would suggest start with the basics. Look at the fuel pump for correct flow and pressure (4-6 psi).

As FT mentioned, are you using the same prop?

 

[Fourwinnsfun]

Hi, has this problem been resolved? I just bought an 07 Four Winns Horizon 200 with the merc 5.0 tks and have the exact same problem...