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Beta Engines fault

We have become aware of a problem with Beta engines where the extended front crankshaft pulley becomes loose and damages the threads and keyways on the front of the crankshaft. This has happened to the engine on our share boat and a relative's liveaboard, both with several thousand hours use. We were advised that this is a well known problem related to loading the front of the Kubota engine crank. Having just bought our own boat with a Beta 43, with 2k hours, do you have any knowledge of this and what preventative steps steps should we take to avoid an expensive breakdown? I understand that it is difficult to check the tightness of the front pulley nut as it requires a specialist extended castellated 43mm socket.

Asked by: Donald Starr  | 3.40pm, Friday 3 April


WW says:

The Beta engines are very reliable, but the large extra pulley mounted on the crankshaft will cause damage if it becomes loose.
Regular checking of the alternator belt tension and the pulley itself would seem to be the best procedure. Ensure that the belts are not too tight as this will cause unnecessary side forces, and make sure that the pulley does not rock. Any movement in the pulley should be addressed as soon as it is detected. Inspections once a month should be sufficient; but if the boat is being used a lot, weekly checks might be in order.
Getting the pulley balanced will help, but it would need to be removed first; if everything is fine leave it alone, if it becomes loose it would be best to get it balanced as part of the fix.

Rupert Smedley  | 2.08PM, Friday 10 April

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