Yanmar Water Pump Impellors

[jakeroyd]

Started my engine(Yanmar 1GM 10) to warm up the oil so I could suck it out for an oil change. Noticed no water coming out of the exhaust. After some fruitless 'unblocking' of the cock I discovered the little sintered hub of the impellor had become unvulcanised from the rubber , meaning the hub was turning but not the impellor. Fixed it with a new impellor which I do every year regardless of condition. This really suprised me. Anyone else had this problem ? (never had this problem on my old Volvo 2002)

 

[sailorman]

common problem
many posts do a search on the forum

 

[Pye_End]

Very comon fault with this engine. They used to replace them free of charge for this, but don't know what the current situation is.

 

[capricorn]

Had same problem last year with my 2GM20.

 

[cliffordpope]

Does the impeller actually degrade, or is it a problem that it sticks to the casing from standing, and then rips when first started? Clould some additive/lubricant be added when laying up? Would it help to turn very slowly by hand the first time? I'm thinking of central heating pumps that stick over the summer and then burn out when first turned on. One is always advised to give them a manual twiddle to get the spindle free first.
Or alternatively simply remove the impeller and replace next year, rather than waiting for it to fail just when really needed.

 

[l'escargot]

How old is your impellor, there was a whole batch of these four or five years ago.

 

[jakeroyd]

Not sure , lescargot, I bought the boat this spring and had a spsre but did not fit it , so it could be say 2yrs old , manula says replace every 1000 hrs , but mine had only done about 100hrs this year.
Appears to do it with no warning , I might inspect my new one vevry month or so next year

 

[l'escargot]

The one I have in use at the moment is in it's third season and was purchased after the reported problems. You may have just been unlucky and the one you have was old stock from the problem batch.

 

[Gunfleet]

I keep my boat on the east coast and have had it happen three times in four years. I keep a couple of spare impellors on the boat at all times. One isn't enough because there's nothing to say you put a new one on and that doesn't go too. Yanmar couldn't give a toss abt it, in my experience.

 

[wiggy]

mine went today, the second one this summer, mind you i keep old ones so may have fitted one I removed for a routine change. i really must keep track of the spares on board!!!!!

 

[Gunfleet]

I've often thought you could secure them with a self tapping screw into the body of the impeller. But you'd need nerves of steel to do it!