Yanmar 4JH3-TE 75hp

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Caladh

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Has anyone got experience of these engines? I am about to purchase a sloop with one of these fitted an wonder if it might over -power a 10 ton 39 foot yacht? Is the turbo problematic a slow revs ? The 4JH3 appears to come in various "sizes" from 56hp up to 75hp so I guess uses the same block.

Hope someone can furnish me with some info.
 
Caladh said:
Has anyone got experience of these engines? I am about to purchase a sloop with one of these fitted an wonder if it might over -power a 10 ton 39 foot yacht? Is the turbo problematic a slow revs ? The 4JH3 appears to come in various "sizes" from 56hp up to 75hp so I guess uses the same block.

Hope someone can furnish me with some info.
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As far as I gather -the lower end of the range is normally aspirated while the higher power variants are turbo diesels.(AE versus TE engines) Much the same mechanicals otherwise- though probably better cooling on the Turbos? Turbos in general seem to kick in about 2200RPM, though somebody may dive in to deny this! I would think if you have a TE version you should have plenty of power in reserve- assuming the prop is appropriately sized?
 
I have a naturally aspirated 4JH4E, 50 odd bhp, I think it's 56 bhp, but only for a short period, less for continuous operation.

It's powering a 46ft, 16 ton yacht.

With a clean hull and calm conditions I get 7knots at 2,000rpm and hull speed (just over 9 knots) flat out. The prop is a three bladed Max prop.

So I'd say that 75bhp is well over powered for a 39ft 10ton yacht, assuming it's fairly slipper shape and not a barge.

I've never used a turbo on a yacht, but the folk law suggests that turbos' are problematic if not used regularly, OK on fishing boats which are used day in and day out, but not good if left idle for long periods.
 
Turbo engines are not a problem. Just be sure to use decent oil, and change it at recommended intervals. Also be sure to let the engine idle for 5-10 minutes before switching off, to let the turbo cool down. My old boat had a Volvo Penta 2003T turbo engine, 24 years old, original turbo, ran beautifully.
 
I have a Yanmar 4JH2DTE (88bhp) in a 45 foot yacht, and it is over powered, making 7 knots at about 2250 RPM and I have never taken it beyond 3000 RPM, at which speed its trying to push the boat up its bow wave at close to 9 knots! As for the turbo, that is no problem as its using the turbo at cruising RPM. The cool down always happens because in stern first mooring I always let the engine run at tickover speed in gear whilst I drop the sails, put out fenders and motor astern into a berth, so that I can actually cut the engine as soon as the boat is tied up.
 
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