2008 20SSV Black Smoke Issue

[Redenvy]

So my boat seems to be running fine with the exception of lots of black smoke this year. It has the 325 EFI Indmar. If you are sitting on the back of the boat while idle you will choke on it. Anyone have an idea of the cause. The boat is still running about 40MPH seems to run\idle OK. I have had a little more vapor lock this year then normal as well if that helps. I replaced the WATER TEMP Sendor Sensor tonight and that didn't seem to help. Maybe a throttle position sensor?? Attached a pic from the back of my boat tonight of how how much black smoke build up is coming out of my exhaust. If anyone has any thoughts please let me know.

17383

[bears74]

Black smoke is unburned fuel. Check your spark plugs, I would bet you will find one that smells like gas it just hasn't fouled yet. I would guess that you have a bad injector that's dumping excess fuel.

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[bears74]

I'm assuming that it's port injected and not throttle body?

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[Redenvy]

Thanks, cap looked a little oxadized. Replaced cap/rotor and ordered new plugs too. Maybe it just a tune up. I Tuned it up last summer, and only put 35 hours on it but maybe it needed another. Here's to hoping this fixes it.

[Redenvy]

Thanks, cap looked a little oxadized. Replaced cap/rotor and ordered new plugs too. Maybe it just a tune up. I Tuned it up last summer, and only put 35 hours on it but maybe it needed another. Here's to hoping this fixes it.

Replaced Cap Rotor and plugs again and the issue pursued. Talked to a guy at the dealer, and he thought it was probably a stuck injector, and to add 4 cans of seafoam with my next tank of gas. Then run it for about 20 minutes at higher RPM's. Sure enough this I added the seafoam and went for a long boat ride and the issue went away.

Boat is running like new again!!!

[CJD]

Thanks, cap looked a little oxadized. Replaced cap/rotor and ordered new plugs too. Maybe it just a tune up. I Tuned it up last summer, and only put 35 hours on it but maybe it needed another. Here's to hoping this fixes it.

Yep...Bears said it was likely an injector. Pulling the plugs was just to see which one.

[Redenvy]

Yep...Bears said it was likely an injector. Pulling the plugs was just to see which one.

Pulled the plugs and they all looked the same before the seafoam. They were all pretty black with nothing looking different between them.