smoking Yanmar 4JH4 - HTBE

[Shunpiker]

I attended the survey yesterday of a 2007 Island Packet 41 SP Cruiser I have under contract.

The engine, model referenced above, would not under load/WOT reach what the surveyor said should be max rpm of 3,800. Max rpm under load at WOT was 3,400 with dog of 6.5 knots with copious quantities of black exhaust/smoke.

With no load on the engine it turned 3,800 rpm with no smoke.

Do any of you gentlemen with expertise I lack have thoughts as to the cause?

Thanks for any advice/lessons.

[hpeer]

I will leave the black smoke aside for others.

We have a 2006 Yanmar 4JH4 TE, that is 72hp. It has 2,600 hours.

My redline is 3,200 and I can reach that in gear. I seldom tun the engine over 2,200 and get about 6.5 knots out of that. She is pushing uphill at a bit over 7 knots.

Now mind you I am pushing a 44’ steel sailboat weighing in at 40,000 pounds with a 37’ (or a tad less) waterline. The Island Packet is only 23,000 pounds.


I don’t know what an HTBE is. I found a site inline that says it is 110hp. A HTE is turbocharged with an intercooler, has a rating of 110hp @ 3,200 RPM.

https://www.yanmar.com/marine/wp-con..._022021_HR.pdf

My thoughts.

I suspect the redline for that engine is 3,200 the same as a HTE. If you got to 3,400 then thats good, perhaps a but under proped.

Thats a LOT of motor for that boat. I would think that that boat/motor combination would be pretty poorly matched (unhappy) running at those power levels.

Before ANYTHING else I would confirm, with my own eyes, the model number and manufacturers specifications.

NEVER blindly assume the surveyor knows anything. Some are wonderful, but not all.

PS:

This site CLAIMS 9 knots for that boat motor combination. Still not buying 3,800 rpm.

https://plymouth.boatshed.com/island...at-151665.html

[jamhass]

Likely over-propped. If you are lucky, the prop may have adjustable pitch -- think MaxProp, etc.

[skipperpete]

Originally Posted by Shunpiker

I attended the survey yesterday of a 2007 Island Packet 41 SP Cruiser I have under contract.



The engine, model referenced above, would not under load/WOT reach what the surveyor said should be max rpm of 3,800. Max rpm under load at WOT was 3,400 with dog of 6.5 knots with copious quantities of black exhaust/smoke.



With no load on the engine it turned 3,800 rpm with no smoke.



Do any of you gentlemen with expertise I lack have thoughts as to the cause?



Thanks for any advice/lessons.

Did you do the out of water survey first and then the seatrial? If so that would exclude a shelled up propeller as the cause of the black smoke. If the prop is clean then it might be overpitched but it’s also possible that the turbo compressor is dirty OR the turbo is not spinning up due to corrosion or heavy soot buildup.

[Shunpiker]

Thank you for your time and thoughts. The boat was designed as a Motorsailer, hence the 110 hp engine.

[JimsCAL]

Check for dirty bottom/prop first. If clean, find a good engine mechanic to do an engine survey.

[mcconkd]

If you think the engine is a 110HP turbo, the correct Yanmar number is: 4JH4-HTE. It is real easy to tell, just look to the rear of the engine and see if there is a turbo unit there, if there is it is as stated.

[Stewie12]

Definitely an engine survey.

[lhuff35204]

We spent thousands on the same issue. IT WAS THE PROP. Don't spend a dime on the engine until you evaluate the prop.

[hpeer]

The surveyor told the guy it should rev up to 3,800 RPM but only hit 3,400.

The rated HP is at 3,200RPM.

The boat was only making 6-1/2 knots @ 3,400RPM while stated max is 9 knots.

Maybe the tachometer is way off. Did surveyor check its accuracy?

CONCLUSION:
A- Get a different surveyor.
B- Engine is not OVER proped if it over revs.

[Celestialsailor]

Dirty prop...Dirty bottom

[JohnHolland]

Reading that a dirty turbo usually makes white/grey smoke due to incomplete fuel combustion..will.smell like diesel fuel. Take off the aircleaner housing and carefully try to spin the turbo compressor side turbine with your finger...it should spin easily 1-2 revolutions. Oil and.soot inside the housing are also an indicator of a dirty turbo system. Yanmar manual recommends cleaning with 'IHI blower wash' every 150 hours, or w clean water every 50 hours as preventative maintenance.

[SteveSadler]

Black smoke means restricted air. First look at the intake screen for belt dust buildup.

[Paramotorgreg]

Reference the black smoke, I would suggest that you check the Turbo unit. I have had similar from my Yanmar when the turbo had failed…extra fuel at higher revs, but lack of extra oxygen leads to incorrect combustion.

In my case the fix was relatively easy and inexpensive, the turbo was cleaned and serviced - by a competent Yanmar engineer, not by me .

[Shunpiker]

Thanks to all of you for your thoughts.

Having now received and read the survey report (and photos of the plate on the engine) I know I incorrectly identified the engine in my initial post relying on the “specifications” in the listing. The engine is in fact a Yanmar “4JH3 - HTE”. What difference, if any, that might make I know not.

In the event, I have tendered an acceptance of the boat conditioned on sellers repairing/restoring the engine output to factory specs, along with a few other items. I lean toward thinking the suggestion that the turbo is simply dirty is likely correct but will leave it to sellers technicians to solve.

I will print your replies for the maintenance tips. If I can get her bought I’ll get the engine on a maintenance schedule.

Thanks again