Could a Mis-Aligned engine cause loss of power?

[Supratrb]

I recently took my 4.3L 2005 Crownline 206LS to get the fuel pump replaced. When I got it back, they told me they had to take the outdrive off as well as lift the engine to get to the fuel pump. Ever since I got it back, there have been vibrations and a loss of power. For example, I had 5 people in the boat and I had to get everyone to the bow of the boat just so it could plane out at full throttle. Once the boat does plane, it cruises in a straight line but you can forget about any 180s or 360s. With the load of 5 people the RPMs would stay around 2800 under WOT and could/would not go higher until I moved everyone to the bow. Once in plane, the RPMs reach around 3200-3800(max) under WOT. The boat did not have this problem before I took it to the shop. I checked the Fuel pressure and it's 52 psi. There is fuel in the fuel rail and the exhaust does not smell too rich or too lean. The engine starts and revs smoothly in neutral. I understand that the misalignment could be the cause of the vibrations but could it also be the loss of power???

 

[Gary H NC]

Re: Could a Mis-Aligned engine cause loss of power?

I doubt it.If it was off that bad the coupler would be gone by now.
Sounds like the shop has something hooked up wrong or the new pump is defective.

 

[zbnutcase]

Re: Could a Mis-Aligned engine cause loss of power?

No!

 

[jtmarten]

Re: Could a Mis-Aligned engine cause loss of power?

Doubtful. If it IS misaligned, I'd certainly look for another shop.

 

[Supratrb]

Re: Could a Mis-Aligned engine cause loss of power?

Thanks for the input! Any idea as to what could be causing this?

 

[jtmarten]

Re: Could a Mis-Aligned engine cause loss of power?

Did they do any other work, timing, etc? Maybe they have it still set in base timing mode, so no advance.

 

[Supratrb]

Re: Could a Mis-Aligned engine cause loss of power?

No. I knew what the problem was before I took it in and told them to change the Fuel pump. It took them long enough just to do that (3 weeks), I wouldn't ask them to do anything else. I'll check the timing and plugs.

Thanks

 

[Supratrb]

Re: Could a Mis-Aligned engine cause loss of power?

I've checked the plugs and the distributor looked like it is fixed in the position it's in. Everything checks out OK.

What I am having a hard time understanding is how a misaligned engine could cause vibrations but no loss of power. Obviously, if there are vibrations, this would mean that not all of the engine's power is going directly into the driveshaft and prop. I understand that a little misalignment would be compensated by the U joints and Gimble but would it still channel and dampen enough to put the power of the engine to the prop?

 

[KJSmitty]

Re: Could a Mis-Aligned engine cause loss of power?

I understand that a little misalignment would be compensated by the U joints and Gimble but would it still channel and dampen enough to put the power of the engine to the prop?

Actually the U-joints and G-bearing would not compensate for a poorly aligned engine. Your coupler however would - until it fails..

If you have "new" vibrations and other issues following this repair you basically need to check their work - either by returning it to them, taking it to another shop and/or performing the checks yourself.

Bummer

Good luck

 

[NHGuy]

Re: Could a Mis-Aligned engine cause loss of power?

Engines need to be properly aligned after removal. A quick check you can do if the boat is still in the water is to run it at the dock. Since the driveline spins all the way down to the lower unit you can turn the steering back and forth while idling to see if there is more vibration when the steering isn't centered. Either way, I'd start out by checking the engine alignment before you run it any more. They probably think they left the mounts the same way they were when they pulled the motor. If it's out of alignment the gimbal, coupler and u joints are getting a beating. If they didn't recheck the alignment when they put the engine back on the mounts it may have gone to a different angle and they wouldn't know. Just because they didn't change the settings doesn't mean all is well.
Sorry to hear of your dilemma.
If you are mechanical an engine alignment isn't really technical, you just need the alignment bar and the time to pull your drive to do the work. The rear of the motor stays in one spot, you move the front of the engine up & down with the mounts, and you angle the gimbal with the bar which is a tight fit into the gimbal bearing.
3 weeks, no boat in summer. Arghhh. Maybe you should complain so you don't have to do it yourself, but you know they will take too long.