Too much exhaust soot?

[gfuller]

Hey all,

New to me boat here... I ran about 150 miles the other day at cruise and noticed some soot buildup on the hull. I know this is somewhat normal with a diesel but wanted to make sure I'm not potentially over-propped here and see what you experts have to say about it. I run at 3850 WOT, 19x19 prop, no smoke after warm-up, Yanmar.

Thanks!

[Tree]

I get some at time on the water line - probably a bit heavier than that. I think most of mine comes from leaving the marina berth to the harbour entrance where I'm not spooling the turbo up fully.

[RobS]

How are you verifying your WOT rpms - dash tach or phototach ?

How old is the fuel?

Polish the area with Rejex for easy soot cleaning…

[jleonard]

Diesel exhaust contains soot. No way around it. Depending upon other conditions such as water temp, air flow, etc it can condense and form deposits on the hull.
Yours did.
It does not look unusually heavy to me for a 150 mile run.

[socalmike]

Just make sure your getting a full 3850 with a strobe. That looks normal for 150 miles.

[Serenity]

Are you running 3850 for the entire 150 miles? Your power plant has to be crying!

[gfuller]

Definitely not running 3850 for the entire 150 miles - more like 3300-3400.

This was measured using the onboard Yanmar Tach. I'm aware this can be off... I do have a flowscan that I was considering hooking up. Is the potential inaccuracy at the gauge itself or the pickup on the motor? I haven't even checked to see if the gauge is mechanical or not but I'm assuming it very well could be considering the analog needle/hour meter.

Thank you for the tip on the Rejex!

[RobS]

The gauge is inaccurate. Not the flywheel sensor.

[gfuller]

Thanks Rob - I'll try connecting the flowscan this weekend.