YANMAR 1GM w/fresh water cooling

[Robert Pierce]

I have 25D with a Yanmar 1GM that was retrofitted with a fresh water coolant system a couple of years ago. Since there is no raw water in the engine rather antifreeze/coolant, is it necessary to change the engine zinc if yes how often? My concern for changing yearly is the hastle of having to drain and dispose of the coolant. I guess this same question can apply to the water impeller as well. I have not changed it in three years and all is well (I do have replacements on board).

BTW, I do ZINC the prop shaft.

Thanks for any input.

Robert
CD25D
Borden Light Marina
Fall River, MA



Robert-Pierce@attbi.com

[Bob Ohler]

If there is a zinc is on the raw water side of the heat exchanger, and I would guess that there is, then you should check that zinc at least once per year. I would go ahead and "service" the internal engine zinc on the Yanmar 1GM at the same time.

If you are not changing your impeller at least once per year, you are tempting fate. If you think that they are a pain to change while you are in the slip, imagine what it is like out on the water with an over heated engine, while you fish the tiny screws out of the bilge. Yoy carry extra screws too, I hope.

Bob O.

I have 25D with a Yanmar 1GM that was retrofitted with a fresh water coolant system a couple of years ago. Since there is no raw water in the engine rather antifreeze/coolant, is it necessary to change the engine zinc if yes how often? My concern for changing yearly is the hastle of having to drain and dispose of the coolant. I guess this same question can apply to the water impeller as well. I have not changed it in three years and all is well (I do have replacements on board).

BTW, I do ZINC the prop shaft.

Thanks for any input.

Robert
CD25D
Borden Light Marina
Fall River, MA

[Dean Abramson]

As for the impeller, I agree that not at least LOOKING at it once a year is indeed tempting fate. I once went through three in one season in my 1GM! I think I hit a batch of bad ones. I strongly urge anyone with a 1GM to buy a Speedseal cover for the water pump housing. Makes impeller checks/changes a snap. Best money I ever spent on my boat. Plus the cover seems to have magic healing properties. Since I installed it several years ago, I have never had an impeller failure. (Sorta like how reefing kills the breeze...)

Dean Abramson
CD 25D "Mariah"



dabramson@mainephoto.com

[Robert Pierce]

Where did you purchase the speedseal cover? I would be interested in getting one.

Thanks

As for the impeller, I agree that not at least LOOKING at it once a year is indeed tempting fate. I once went through three in one season in my 1GM! I think I hit a batch of bad ones. I strongly urge anyone with a 1GM to buy a Speedseal cover for the water pump housing. Makes impeller checks/changes a snap. Best money I ever spent on my boat. Plus the cover seems to have magic healing properties. Since I installed it several years ago, I have never had an impeller failure. (Sorta like how reefing kills the breeze...)

Dean Abramson
CD 25D "Mariah"

[Dean Abramson]

Robert,

I bought it direct from Speedseal in England; ordered w/ credit card, and it came right away. See their web site at www.speedseal.com Good photo of one there, right on their home page. Also, they advertise frequently in the back, in the gear section, of Cruising World. Really, this is the best value-for-money I've ever found for my boat. I had been using a vicegrip to come at those Yanmar cover screws from the side, replacing the screws periodically as the heads got chewed up, but still it was a bitch. The Speedseal screws have these big ole knobs: I tweak them SLIGHTLY with a pliers, but, really, you could probably just go with hand pressure. My memory (I'm not in the boat right now) is that I only remove ONE of the Speedseal knob-screws: the cover is notched so that you only have to LOOSEN the other two, and the thing slides on/off laterally. You are going to LOVE this sucker. They make them for many different engines besides the 1GM. Good Luck.

Dean Abramson
"Mariah"
25D

Where did you purchase the speedseal cover? I would be interested in getting one.

Thanks

As for the impeller, I agree that not at least LOOKING at it once a year is indeed tempting fate. I once went through three in one season in my 1GM! I think I hit a batch of bad ones. I strongly urge anyone with a 1GM to buy a Speedseal cover for the water pump housing. Makes impeller checks/changes a snap. Best money I ever spent on my boat. Plus the cover seems to have magic healing properties. Since I installed it several years ago, I have never had an impeller failure. (Sorta like how reefing kills the breeze...)

Dean Abramson
CD 25D "Mariah"

dabramson@mainephoto.com