Sudden vibration/loss of power/then ok!

[GIZMO]

When we hit the sand bar it also bent the prop. The dealer took care of the prop. Then I described the noise to them and they contacted the facyory. They told us the center fin should be slightly out of alignment.
If it's not the front fin causes the center fin to cavitate and vibrate. (thats the way I understood it I could be wrong) but if your rear fin is bent that is definitly a good place to go next. Just tweek it a little and see if the noise changes.

GIZMO

[Tige M.D.]

you might want to have a fuel psi test done. the fuel pump will start screaming at you when it gets tired. this could also have to do with your loss of power.

the acme prop will change your top speed of your boat. what i need to know is, did the wide open throttle (wot) change?

i have never heard of the bent fin theory? i am going to call and check on this. maybe i will learn something new

[CiceroJoe]

Interesting

I went from a 3 blade to a four blade acme. When the three blade was on there the rev limiter was activating and the top end was around 33-34 mph. Now the hole shot is slightly boggier but top end goes to 42 mph. But now that I started hearing that whine I described in an earlier post with more detail, top end is 37mph. The boat is a 2002. Tige MD, you think a new fuel pump would cause this noise and be suspect after only two seasons?? I'm looking into the prop alignment issue this saturday at the pole barn where its at. I gotta see this.

Those fins are pretty stout and beefy, should take a hell of a whack with a mallot to angle them off center.

GIZMO, did the dealer/factory tell you what angle for the center fin???

[CiceroJoe]

Pics

boat pic

[CiceroJoe]

anotha

Thinking about putting on WCG...

Think it would look good?

[CiceroJoe]

My boat pic

Here's mine

[Tige M.D.]

we ave to use a 4 ton porta-power to move a fin. good luck using a mallet.

mercruiser fuel pumps are very susceptible to failure if the fuel gets old and sticky or there is too much resistance (vacuum) before the pump ie. clogged pre-filter. the fuel pump uses recirculated fuel to cool itself, if the is a lack of recirc'd fuel or the pumps ports are clogged the it will get hot and start screaming. just have someone do a fuel psi test should be between 32-36 psi with the regulator disconnected from the engine vacuum. this will simulate full throttle.

[CiceroJoe]

Right

No mallot. Gotcha. I'll check into the fuel pump issue.

Thanks Tige M.D.

Got 2 new fat saks for the boat for this summer, along w/some fusion speakers..