Yanmar blowing Black smoke....

[yourtruenorth1]

I have a 6 year old Yanmar 4JH4-TE and a 24" Maxprop on a CSY 44 w/o. I did bottom paint in the end of June and yard serviced Maxprop. Since then, I have had black transome soot mustache and seem to have lost some speed. Mechanic advised me that prop was over propped, so I called the yard and asked if they could check the settings and that maybe it didn't go on same as it came off. They agreed to. PYI, Maxprop's tech said with my engine and prop I should be pitched at 16 degrees. Mechanic swears I'm over propped and we should take to next setting which is 14 degrees. Has anyone had similar issue or same configuration that knows their settings? This is going to cost a yard haul and block now that they had it on the manufacturer's recommended setting.

Any ideas why else I might be blowing black smoke and losing a bit of power?

Steve

[CAELESTIS]

Over-propped. Lack of air/turbo boost.

Have you considered a diver to change the prop setting? PYI recommended a diver to change my pitch in the water.

[yourtruenorth1]

This is a classic 3 blade Maxprop, I'm sure it can be done, but not as easy as the current models in the water. Not even that easy while in yard and blocked!
Turbo may very well be something to look at. Thank you

[clownfishsydney]

Over propped is correct, same as ours (I have not fixed yet as minor).

[CAELESTIS]

Yanmar makes (or private labels another company's chemical) a product called turbo-wash that might help with your turbo. If the engine has been run at low rpm's for an extensive period, the injectors may be fouled as well as the turbo.

I still think the prop is the cause from your symptoms. How close to 3100 rpm can you pull underway?

[sy_gilana]

The prop is set too high. I did a re-pitch job in the water with scuba. All you really need is good light and a bucket on a pair of lanyards sunk near the shaft with a diving weight in it. Put all the bits into there. Calm waters help too.

[SimonV]

Check the simple things first. Is your engine breathing right look at the air filter.

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[Bohemian17]

If you're not getting the proper wide open throttle rpm therein lies the problem. Reduce the propeller pitch until you reach that level. I never run run a yanmar unless I can reach the proper maximum wide open rpm. If you're still blowing black smoke then look at the fuel restriction issues start with the filters and work your way back to the tank

[J Clark H356]

My MaxProp is 12 years old and needs a rebuild. I would run 3600 RPM and have cruised for years at 2750. Took our boat to Florida last winter from Kentucky Lake and had lots of soot and high fuel consumption. I never run at 100% throttle so didn't realize what the problem was until back in Mobile 3/4 through my cruise. Max RPM was now 3100 due to worn MaxProp and so I was running at nearly 90% RPM, thus high fuel consumption and lots of soot. Changed injectors and adjusted valves and returned to Kentucky Lake. Will send off Max Prop at haulout for rebuild. Cost $1250 for complete rebuild. Suggest you look into that option if when you pull the blades and they show play.


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[donradcliffe]

Read post #5

http://www.cruisersforum.com/forums/...te-100796.html