Yanmar 3gm30fc

[jax]

The water pump on this engine is fitted with the impeller access plate at the back and the pump has to be removed to change the impeller i.e. in my humble opinion it's fitted the wrong way round. Spoke to the reps on the yanmar stand at the boat show and was told " it ony takes a few minutes to remove, change the impeller, and re- fit the pump" Agreed - but sometimes in an emergency a few more minutes you just 'aint got! Wonder if anyone has addressed this problem - or is there a conversion available?

 

[jfkal]

Easy way out. I carry a full assembled water pump as spare. If you impeller goes and even if you could access from the front, how do yeu get the old one out in an emergency? I prefer to change the whole pump and replace the impeller later

 

[dickh]

Fit a "SpeedSeal" - you can change the impellor blindfold without tools - don't know about the Yanmar - speak to SpeedSeal direct - www.speedseal.com or .co.uk I think

dickh
I'd rather be sailing...

 

[ParaHandy]

I don't think it would be easy to reverse the pump. One problem is getting the small bolts off. I think there are 6 or 8 and the thread is M4 or 5? They can be very difficult to undo and, eventually, because they are made of quite soft metal, the edges burr. Somebody sells a knurled head replacement which allows you to remove them fairly easily, it is claimed, by hand. I'm not sure about that because normally you're up to your armpits (when this happens) in greasy water etc and I would be concerned about getting them tight enough by hand to stop them vibrating loose?

Might be worth trying? Alternative would be M4 capheads for which a shortened Allen Key would be needed - that's what I am going to do. Cheaper.

Once the cover is off, if you regularly replace the impeller, ie annually, it should slip off quite easily.

 

[JerryHawkins]

I've got a 3GM30 raw water cooled. I've fitted a Speedseal cover. This is quick to remove and replace without tools and I have a pair of 'cranked' pin-nose pliers to remove the impeller.

Look at http://www.speedseal.co.uk

Cheers,

Jerry

 

[jax]

Thanks for your replies. I am aware of the ‘Speedseal’ cover plate. I do inspect the impeller regularly, using the boat for four months of the year; I remove it when I leave the boat and check before either refitting or replacing it when I return. I have not had a problem removing the plate or the impeller once the pump is off. I believe that the ‘Speedseal’ costs +/- £50 which seems a bit costly, Why not get half a dozen thumbscrews with split washers under? But this is not the problem. I think I will try to modify the bracket so that the pump can be reversed. Even though this might mean altering the inlet and outlet fresh water pipes, (the direction of flow MAY be reversed) This will make the cover plate easily accessible. I will not know if this idea is feasible until I get back to the boat in February. Apart from this complaint I am satisfied with the engine.