Engine Problems

[Equinox]

Unfortunately I seem to have a little problem with my yacht engine at the moment. It starts ok and runs ahead and astern when out of gear without any problems. However, as soon as I try to run it ahead or astern when in gear and on load it cuts out but no buzzers sound on the panel. I haven't had time yet to investigate it fully but was wondering what the possible causes of this might be.

The advice I've had from this forum in the past has been excellent and would be much obliged once again if somebody could point me in the right direction with regard to this little engine problem.

Many Thanks.

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[Moose]

something round the prop?

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[bob_tyler]

Without the engine running, try turning the shaft. First in neutral the in gear, ahead and/or astern.

If the shaft turns OK in neutral but not in gear I would suspect a seized gearbox (could be very expensive I'm afraid)

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[Keith]

if the shaft turns when you put it in gear and it cuts out shortly after i would change the fuel filter as it sounds tome likefuel starvation under load.........keith

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[cliff]

Unfortunately your bio is a little vague as to what yacht / engine(s) etc which might have been a help but...

First I would look at the propellor for fouling - maybe possible to see it from the pontoon or from you tender. If all looks clear then the next place I would look is inside. Engine off and box in neutral - does the prop shaft turn by hand? if not check the stern gland - dry and over tightened?
If you cannot turn the shaft by hand with the gearbox in neutral and the stern gland is ok then looks like gearbox problem but you say the engine cuts out when you engage the gears - does it just stop dead or does it labour for a few seconds and stop or does it slowly slowdown and stop. Does the shaft turn when this is happening and does it (g'box) make "funny" noises?

Because the shaft does not turn by hand while in gear does not mean a problem with the gearbox - I can hardly turn my engine over even with a crank handle, 2:1 reduction gearing and decompression so I ain't going to turn it by using the propshaft.

If the shaft turns by hand we can assume the gearbox output shaft is OK.

What type of gearbox is fitted - some can only "engage" when the primary input shaft is driven as they use oil pressure to close cone clutches (twin disc or double cone type) others are crash boxes with no synchromesh others are syncromesh gear - the latter 3 types do not require the engine to be running to work.

If happy there is nothing wrong at the drive end then I would look at fuel starvation (change the filters and clean out all fuel lines upstream of the primary filter and if gunged up clean out the fuel tank) or something exotic like, has anyone been working at the engine recently? any possibility of the fuel being cut off when you engage gear - some gear boxes have interlocks to prevent starting in gear - anyone been changing any senders or rewiring - I know it is a remote chance, a very remote chance, but.......

A good aid to the diagnosis is how the engine stops. Can you be more specific?

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