3055 Can(39)t get full power....-gctid399832

[Guest]

We have a 1999 Ciera 3055 with just under 300 total hours on carbureted 5.0 L engines. Have owned the boat for seven years (had

[carguy]

1st off, welcome aboard.

Secondly, that is a weird problem. Let's do a little more diagnosis. Next time out, run WOT on only one engine at a time. I suspect that the starboard engine will put out a lot more power than the port. Initially, it appeared that it's possibly a fuel issue but that would affect both engines equally (with some exceptions ie individual fuel pump. If I'm correct, we can at least narrow it down to a port engine issue and go from there.

It is also odd that you can only make 4100 at WOT. It might be worth a call to bayliner. If you give them your hull number, they'll tell you what props were originally on the boat.

Doug

[Stratocaster]

Before doing anything else, go and buy 16 spark plugs and change them all.

Doesn't matter if the old ones look fine.

I'd bet good odds this will solve your problem.

I have had this happen on two boats and one motorcycle. Always the same symptom...runs smoothly but no power. Change the plugs, boom, back to normal. At least it's a cheap and simple way to either confirm or eliminate this as the issue.

[Guest]

carguy wrote:
1st off, welcome aboard.

Secondly, that is a weird problem. Let's do a little more diagnosis. Next time out, run WOT on only one engine at a time. I suspect that the starboard engine will put out a lot more power than the port. Initially, it appeared that it's possibly a fuel issue but that would affect both engines equally (with some exceptions ie individual fuel pump. If I'm correct, we can at least narrow it down to a port engine issue and go from there.

It is also odd that you can only make 4100 at WOT. It might be worth a call to bayliner. If you give them your hull number, they'll tell you what props were originally on the boat.

Doug

...should have mentioned, props are aluminum, 3 blade, 17 3/4", 21 pitch.

[Guest]

Better check timing as well. And check total advance at speed, you will need the factory distributor advance curve/specs to check this.

[Guest]

I completely agree on changing all the plugs.

Did the change in RPM happen suddenly, like a switch being thrown, or did it happen gradually?

At that point both engines were reading 4100 RPMs. Throttled back to our normal cruise---3500 RPMs and the speed was 24 mph, same speed as we've always gotten. (4100 RPM has been the historical WOT speed ÔÇô yes, I realize that's a bit below recommended, but we've never had trouble getting out of the hole so we've not re-pitched the props).

You are definitely overloading the motors by having your WOT RPM be that low. Also cruising at 24 MPH is wasting fuel and lugging the motors a little. Your boat has only slightly less HP than mine, and my flow meters show that 3800 RPM and 32 MPH is the most fuel-efficient speed.

[Guest]

[QUOTE]SwampNut wrote:
I completely agree on changing all the plugs.

Did the change in RPM happen suddenly, like a switch being thrown, or did it happen gradually?

...suddenly, like a "surge", definitely not gradual increase in RPM.

[Guest]

That sort of behavior suggest an electrical (ignition) problem more than a fuel or compression problem. One thing I've seen cause this is a cracked distributor cap or one with junk inside it creating an alternate electrical path (moisture, corrosion, dirty).

I would do these things:

Full set of plugs.

Remove, clean, carefully inspect the caps and rotors or replace them.

Inspect spark plug wires for cracking, leakage points (burned looking), etc.

Test resistance of the ignition coil.

Inspect coil for signs of oil leakage, damage, burnt spots, etc.

Check timing with the purple wire grounded, then check again for proper advance without grounding it.

[Chief_Alen]

http://www.baylinerownersclub.org/forum/showthread.php?71558-02-2855-350-mpi-saga-continues&p=696607&posted=1#post696607

[Guest]

Thank you to everyone who suggested solutions. Yes, it was electrical -- distributor caps, rotors and spark plugs were replaced on both engines. When replacing the rotor on the engine port engine...the one with the lower rpms, we noticed the ignition sensor looked really bad--corroded and grody...the starboard ignition sensor looked great. We went ahead and buttoned it up but still had problems with the port engine...wouldn't even start. Took a day to chase down an ignition sensor (another $60, pretty reasonable) and installed it.

Fired up beautifully, test run she popped out of the hole like I can't remembering it doing before. WOT is now 4400, so in the recommended range.

Thanks again for all the suggestions!

[Guest]

nice fix, I will have to remember that one.