Port engine spooling up slower than starboard.

[Tomion]

My Carver 444 Cummins 370 port engine is spooling up slower than Starboard engine after reaching 2000 rpms. The port engine start coming up to full rpm after approx a minute or so as the boat begins to plane. I recently had shafts and castle bearings replaced but suspect turbo charger. Any thoughts?

[Viper]

Ya I'd check the turbo. Make sure it spins freely. The turbine should spin freely by hand and take a while to come to a full stop once the engine is shut down. Do you have boost gauges? When was the last time you had fuel service done; replacing filters and disassemble/clean the Racors? Check air filter. Any smoke once she warms up?

You didn't mention replacing props but did you have an impact? If you did, did this symptom exist prior to the impact or only after?

How old is the boat? Are the engines electronically controlled? Is there any indication that the ECM/computer may be dictating the slow response? Any alarms? If you haven't already, it may be beneficial to get a tech in and hook up to the ECM and look for fault codes, and if applicable, update the software. Make sure all connections are clean and tight on the engine harness plugs. It's a whole new ball game with electronically controlled engines.

[Tomion]

Thanks for reply Viper, the engines are 2001 vintage mech fuel injection with 600 hrs. No signifigant smoke. Racors look clean, were replaced a 100 hours back. Shafts were replaced due to groooves worn in them by frozen bearings.

Will check freedom of Turbo chargers and possibly swap them. Thanks

[Viper]

Source of the post....Racors look clean, were replaced a 100 hours back.....

How long ago was that time wise? The condition of the fuel filters will differ from running 100 hours in one year versus the same number of hours over 5 years. Given the cost of them, I'd replace them every year. They're your first line of defense. Ensure there is no water in the bottom of the bowls.

[Tomion]

No water in fuel bowls look clean. I apprently have a vent line plugged on left tank. Any chance of that creating vaccum in tank and caysing slower engine acceleration.

[Viper]

If air can't get into the tank there will be no equalization in pressure. You will eventually starve of fuel. Go for a run with the gas cap off and see if you have the same symptoms. As long as the gas cap isn't in an area that will get wet while underway, you should be okay to do this test. If the symptoms are still there with the cap off, then you need to continue looking but you should still clear the vent line.