prop vibration in hunter 25.5

[sailorkoop]

I'm about to purchase a 1986 hunter 25.5 with a Yanmar diesel. The current owner said because of the 2 bladed prop there is a vibration in the cockpit when running the engine. My questions are: why is the prop only two blades? Can i put a 3 bladed prop on the boat and will this stop the vibration? What will be the effect? Is the vibration normal on a hunter 25.5?

Thanks for your help........I'm new to sailing but learning and reading all i can.

 

[MrUnix]

How bad is the vibration? I ask only because with a diesel engine, you will get some vibration throughout the whole boat.. While I'm not familiar with the 25.5, My previous H27 (which has a similar layout to yours) had an inboard Yanmar and the vibration was most noticeable in the cockpit since that was pretty much directly overhead, but you could still feel it up in the front V-berth as well.

If the vibration is severe, it could be from an out of balance prop, or one that has been banged up a bit. It's pretty easy to visually check it, and pop it off to have it properly serviced if that is the case. It could also be from a bent driveshaft or worn shaft bushings. Either one of those conditions, if left as is, will quickly eat up your stuffing box and produce unnecessary strain on the engine and main bearings.

Cheers,
Brad

 

[Clark]

Two blade props are notorious for vibration but also . .

consider engine alignment to the prop shaft in addition to the other possibilities mentioned. There are procedures available to do an alignment and if one is just a bit 'handy" it is not difficult to do.