Friends 2000 3100 with 8.1 L Crusaders has a major CO...

[Chesfisherman1]

My buddy is in the process of having a marina investigate excessive CO levels. (+300). 

He mention-
Happens on both engines independently.
Increases with RMP.
Used 2 digital CO detectors from 2 companies.
No changes have been made to helm area (has hardtop/glass)

Any feedback would be very helpful.

Chesfisherman

[reeltimebrad]

Is this something new or is this a new boat to him? Possible got some bad fuel. I usually run with the center windshield open and cabin door shut to help with the station wagon effect of exhaust coming back into helm area when running.

[Chesfisherman1]

He has owned this boat for years and maintains to a very professional level. I will report on the root cause once he is checked out by marina.

Chesfisherman

[Dakota773]

Is this a problem in the cabin and in cabin CO2 sensors. I've fund that the sensor cans go bad. One of the manufacturers noted that they should be replaced every 10 yrs.

[Chesfisherman1]

He has CO handheld sensors...agree cabin sensor fail over time.

Update-
Leak not in engine room.
Leak is likely in rear compartment that houses gas tank fish boxes and live well.
I took photos of my exhaust in this area and there is several exhaust components that are potential cause(s)

Marina still has no answer.

Has anyone experienced failure of exhaust components in this area?

[Misdirection]

Those handheld sensors are much more sensitive than one designed for marine use and a fixed mount CO detector.

Similar to how you can not use a household CO detector in a boat, they will give false positives.

So, back to the original problem, is it the CO detector in the cabin going off and has it been replaced?

Sent from my SM-A505U using Tapatalk

[reeltimebrad]

If you suspect a leak somewhere in the exhaust system then spray everything with a soapy water mixture and look for bubbles while the motors are running.

[Chesfisherman1]

The CO detectors are not in cabin and are handheld. He bought 2 sensors from 2 manufacturers to ensure good data during debug.

I like the soapy water spray to all exhaust parts with a visual inspection after starting engine.

For now my buddy is not engaged with his boat allowing Marina to all investigation.

I believe no other input is needed.

I will report back on issue once resolved.

Thank you