Different boat, different engine. Changing the impeller on my 306 was a piece of cake. You might have a 2GM. That has the impeller on the front driven by a separate belt.
Yanmar Impeller Replacement
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Different boat, different engine. Changing the impeller on my 306 was a piece of cake. You might have a 2GM. That has the impeller on the front driven by a separate belt.
If impeller was on front
The front & sides on the engine are fine.
Even the rear isn't horrible.
But burying the water pump under the alternative facing rear is just plain dumb.
Friends of mine who have 49s on board gave had pro mechanics struggle for hours on it.
Unless you had a center cockpit boat with full rear engine room access, this just doesn't work.
I couldn't believe this until I personally saw it.
There would be no issue.
The front & sides on the engine are fine.
Even the rear isn't horrible.
But burying the water pump under the alternative facing rear is just plain dumb.
Friends of mine who have 49s on board gave had pro mechanics struggle for hours on it.
Unless you had a center cockpit boat with full rear engine room access, this just doesn't work.
I couldn't believe this until I personally saw it.
Yup. I understand it is where it is. Why anyone would put that engine where they did is the issue. My contention being Yanmar made the engine before some bright Hunter designer thought that location would be appropriate and no one ever stopped or questioned him.
I was just reading this to read it. But it made me wonder if you could put a remote belt driven water pump on the front of the engine. Then it would never be an issue again.
I bet engine access is something most people don't think about when getting a boat, which is too bad!
In theory, yes.., but
Would be tricky to belt it slow enough.
The pump is run a fairly low speed compared to flywheel or alternator.
Would be tricky to belt it slow enough.
I've replaced my impeller 3 times. Just pull the starter and you can remove the impeller with your fingers. There are only two bolts holding the starter on. You can leave the wires attached. Access hatch? Depends on the interior. Mine has a factory hatch.
Ok, you got me thinking...
I have found the perfect solution.
You can buy what are called crankshaft mounted water pumps.
They basically bolt onto the front of the flywheel, and you have a small stabilizer arm to keep the pump from rotating. I'll need to make a small adapter plate for the flywheel out of aluminum . No biggie.
The the hoses will provide enough static friction, but the arm is a good idea.
These pumps are rated up to 5000 rpm.
Cost approx $200.
So, I'll pull the Yanmar impeller, move the hoses, and I've got a front access water pump. This should be a brilliant solution to an awful problem.
You brought up an excellent suggestion, and I've now seriously looked at this
I have found the perfect solution.
You can buy what are called crankshaft mounted water pumps.
They basically bolt onto the front of the flywheel, and you have a small stabilizer arm to keep the pump from rotating. I'll need to make a small adapter plate for the flywheel out of aluminum . No biggie.
The the hoses will provide enough static friction, but the arm is a good idea.
These pumps are rated up to 5000 rpm.
Cost approx $200.
So, I'll pull the Yanmar impeller, move the hoses, and I've got a front access water pump. This should be a brilliant solution to an awful problem.
Thanks for the tip on the offset needlenose pliers. I need to do the same job, and I have an access plate already.
Did the impeller pull strait out fairly easily or was it hard to pull? Did you grab it by the center or just wherever you could.
I went to a Yanmar dealer for the new impeller. They said they last much longer than standard impellers and that is why the new one was $90.00. I thought that was a little steep, but needed the peace of mind of having the new one.
Did the impeller pull strait out fairly easily or was it hard to pull? Did you grab it by the center or just wherever you could.
I went to a Yanmar dealer for the new impeller. They said they last much longer than standard impellers and that is why the new one was $90.00. I thought that was a little steep, but needed the peace of mind of having the new one.
This price is crazy
They just quoted me $17 for it.
I was surprised it was so reasonable, cause my parts dealer charged me $80 for the last one .
Contact Mastry in Florida.
They just quoted me $17 for it.
I was surprised it was so reasonable, cause my parts dealer charged me $80 for the last one .
1. I replaced my impeller with a Jabsco part #1210-0001P. Much cheaper than Yanmar. Has anyone had experience with Jabsco impellers?
2. Seeing the broken bits of impellers is scary. There should be filters downstream from the pumps to prevent the bits from lodging in the heat exchanger, etc.
3. Wow. Glad I don't have a sub floor engine! That sounds pretty crazy to access something that has to be replaced regularly. Makes me wonder if it wouldn't be better to just abandon the Yanmar pump and install an electric pump someplace convenient. A centrifugal pump would last a long time.
4. It's surprising how some get very long service from an impeller, while others are failing quite soon. Wish it could be predicted better. I've never had one fail, and when replacing them the old ones typically look pretty good. But I'm afraid the flexing will add up and cause a sudden failure.
2. Seeing the broken bits of impellers is scary. There should be filters downstream from the pumps to prevent the bits from lodging in the heat exchanger, etc.
3. Wow. Glad I don't have a sub floor engine! That sounds pretty crazy to access something that has to be replaced regularly. Makes me wonder if it wouldn't be better to just abandon the Yanmar pump and install an electric pump someplace convenient. A centrifugal pump would last a long time.
4. It's surprising how some get very long service from an impeller, while others are failing quite soon. Wish it could be predicted better. I've never had one fail, and when replacing them the old ones typically look pretty good. But I'm afraid the flexing will add up and cause a sudden failure.
Inline strainer
An excellent practice is to put a simple inline hose strainer between the pump & engine with a fairly coarse mesh. The cost is insignificant, and it catches any impeller "bits", if it ever fails.
An electric pump doesn't work for a few reasons
You need about 10gpm. You also need a pump which is rated at continuous duty.
There are only 2 ways to go here;
A continuous rated impeller pump
Or, a magnetic drive airco pump.
The impeller pump had a current draw of 25 amps, (approx)
For your engine, you might get away with 6 gpm, which lowers it to 15 Amps.
In either case, this is a lot of current to be taking out of your alternator.
And, let's say you are motoring a long distance, and your alternator smokes.
Now you've got a 20+ amp contact battery drain. Not good.
Next option is airco pump. Definitely rated continuous duty, but they are all either 120v or 220v.
So, now you need an inverter.
This gets way too uncertain considering that one of the main benefits of a diesel is all you need (typically) is air & fuel.
Much better option is crankshaft mounted pump.
No belts, pulleys, etc.
Total cost $200
Rated at 10 gpm @ 2000 rpm . Very reliable alternative
An excellent practice is to put a simple inline hose strainer between the pump & engine with a fairly coarse mesh. The cost is insignificant, and it catches any impeller "bits", if it ever fails.
An electric pump doesn't work for a few reasons
You need about 10gpm. You also need a pump which is rated at continuous duty.
There are only 2 ways to go here;
A continuous rated impeller pump
Or, a magnetic drive airco pump.
The impeller pump had a current draw of 25 amps, (approx)
For your engine, you might get away with 6 gpm, which lowers it to 15 Amps.
In either case, this is a lot of current to be taking out of your alternator.
And, let's say you are motoring a long distance, and your alternator smokes.
Now you've got a 20+ amp contact battery drain. Not good.
Next option is airco pump. Definitely rated continuous duty, but they are all either 120v or 220v.
So, now you need an inverter.
This gets way too uncertain considering that one of the main benefits of a diesel is all you need (typically) is air & fuel.
Much better option is crankshaft mounted pump.
No belts, pulleys, etc.
Total cost $200
Rated at 10 gpm @ 2000 rpm . Very reliable alternative
