Yanmar 2GM20 Salt water pump replacment - FOUND ONE!

[G12]

I just wanted to share a bit of good info that I was given today.

For those of us with Yanmar 2GM and 3GM engines there is an alternative salt water pump to the astronomically priced (£556+VAT) Yanmar version. This one is made by Johnson. It comes with its own bracket to fit the engine and appears to be a nicely made pump with a proper O ring seal.
Today including the 10% website discount I paid £220 including a spare impeller and shipping from the uk distributor Watermota.
https://www.watermota.co.uk/product/sea-water-pump-yanmar/

More info
http://www.jmpusamarine.com/product...eawater-pump-jmp-jpr-ym08ih02-yanmar-2gm-3gm/

 

[bikedaft]

Cheers for that. Looks like you could put speedseal type knurled knobs in place of the 6 bolts, too

 

[G12]

Yeah, I think you probably could get a speed seal kit for it. I'll investigate... definitely a good mod...

 

[ghostlymoron]

You won't get a speedsteel kit from the manufacturer as he's retired due to ill health I understand. You can get the knurled screws off eBay.

 

[UK-WOOZY]

I recently replaced the 1988 2GM20 pump, £500+ from bottomlinemarine. a refurb was £400.. on my original. I did lots of searching on alternatives and it seems the cheaper pumps are for 2GM20's made after about 1995 ish and are too different

 

[ghostlymoron]

I replaced the seals and bearings of a VP pump which was easy and cheap. I thought most raw water pumps were similar or am I missing something. I got the bits from simplebearings.com. The shaft was ok but a lathe operator could make one for a few quip.
NB the seals need to have stainless springs or they'll corrode in no time.

 

[Old Bumbulum]

http://www.ybw.com/forums/archive/index.php/t-400719.html

Chapter and verse on this old thread. It seems the pump types and differences are numerous and it needs special care to ensure you get the right one or it just won't fit!

 

[UK-WOOZY]

exactly. pre 1996 2GM20's HAS to be the costly £500 pump unfortuanetly, no way around it. ridiculously expensive but at least they are still available. my original pump wasnt priming as it had a big groove in the champer and the spindle was worn

 

[Channel Sailor]

I recently replaced the 1988 2GM20 pump, £500+ from bottomlinemarine. a refurb was £400.. on my original. I did lots of searching on alternatives and it seems the cheaper pumps are for 2GM20's made after about 1995 ish and are too different

So maybe it was worth the smallish investment to fit a decent Vetus intake water strainer on my old 2GM20, to reduce the risk of scoring a groove in the chamber. It definitely catches stuff in the strainer that would have gone into the pump. I had to sand flatten the brass cover plate last year as it had grooves in the surface building up which could have affected priming. The pump could be original at 24 years old. I could guess as a small coastal leisure yacht over its life the engine has done 120 hours a year = 3000 hours. Not a lot I would say for a 2GM20. I fitted the strainer mainly because I reckon chips of antifoul (when prepping for antifoul refresh) from the surfaces of the external coarse grid strainer/skin fitting got into the pump.

 

[UK-WOOZY]

i got the boat end of 2017. it was the original pump. it was ok after priming manually but the hose would get airlocks after heeling over or if the engine was turned off. the boat also had one of those basket skin fittings for the inlet on the hull. i removed that this year and have installed an in-line strainer ike the vetus. Also had to replace ALL engine mounts as the rubber had separated from the metal or was flaking. Got Poly-Flex mounts. have also replaced the two anodes and have changed the gearbox and engine oil and filters and belts.