Visit our Popular Forums

goboatingnow · 28-09-2021, 02:01

Quote:

Originally Posted by Tortuga's Lie

If you think the 4JH3 is hard to change out the impeller, try my 3JH! it has even less space between the starter and the water pump, maybe an inch and a half at the most. No room to use the Yanmar remover, only those right angle pliers will work and yes, I do remove the alternator to do this but I swapped the alternator wires for longer ones so I don't have to disconnect anything, just unbolt it. I use heavy tape to cover the wire leads as to not short the leads. The whole process now takes about a half an hour.

Why do yanmar turn the water pump plate towards the engine body. I hate , really hate that

My little Volvo has a gear pump and the plate faces outwards , piece of cake

In my yanmar I always ended up taking the whole pump off

Long ago I bought both sizes of the Jabsco pullers. Best thing ever

Putting then back I pre bend the tines in the correct direction and secure with a tie wrap. Bit of washing up liquid and hey presto , easy peasy, the tie wrap pops off as the impeller slots home.

HeinSdL · 28-09-2021, 02:56

And do make sure the threaded end of the threaded impeller is facing out...

Tortuga's Lie · 28-09-2021, 03:27

I believe Yanmar has seen the error in their ways and now build their engines with the impeller plate facing the front of the engine. I suppose those sadists engineers that designed mine have now since retired! I bet they've never actually worked on an engine before.

This really can be thought of as a safety issue as well, as you may be in a situation where your over-heating engine can't get you out of a jam.

glanrock · 28-09-2021, 04:42

We have the same engine and went through this not long ago. We have the tools that make it somewhat easier by far, but the biggest issue for us was the inability to both see what you are doing and do what needs doing at the same time! The view is minimal.

We're also on the Chesapeake! Hopefully since this thread is a month old you got it done already. If not you can borrow our tools, LOL!

**noelex 77** · 28-09-2021, 04:59

Quote:

Originally Posted by glanrock

We have the same engine and went through this not long ago. We have the tools that make it somewhat easier by far, but the biggest issue for us was the inability to both see what you are doing and do what needs doing at the same time! The view is minimal.

When installing this engine, boat manufacturers should provide engine access from the port forward area. It is not a job that should be done blind.

Why do so many manufacturers not plan for routine service of at least the more common items?

Tortuga's Lie · 28-09-2021, 05:13

Quote:

Originally Posted by noelex 77

When installing this engine, boat manufacturers should provide engine access from the port forward area. It is not a job that should be done blind.

Why do so many manufacturers not plan for routine service of at least the more common items?

Exactly!

glanrock · 28-09-2021, 05:28

Access to the alternator isn't exactly great either, but a far cry better than the impeller. The impeller job was completed actually by my wife who has smaller arms and better able to get her self crammed, angled, with the tools to get the job done. I'm a lucky fella! She reminds me all the time (and I always agree!)!!!
Otherwise though, we absolutely love our boat!

Gudgeon · 28-09-2021, 12:47

Can someone provide the part number for the Yanmar puller please?

**noelex 77** · 28-09-2021, 13:16

Quote:

Originally Posted by Gudgeon

Can someone provide the part number for the Yanmar puller please?

For the threaded type impellers. The part number is:

129671-92110

Gudgeon · 29-09-2021, 11:44

Thanks

**bstreep** · 30-09-2021, 16:50

We have an older 4JH. No threads. We use a modified Seadog puller (we had to cut the screw tip down for clearance).

https://sea-dog.com/groups/3155-impeller-puller

sv_pelagia · 30-09-2021, 17:29

Quote:

Originally Posted by bstreep

We have an older 4JH. No threads. We use a modified Seadog puller (we had to cut the screw tip down for clearance).

https://sea-dog.com/groups/3155-impeller-puller

but you can use new impellers with threads (and thus the Yanmar puller)

S/V Reveille · 30-09-2021, 18:12

Great info... much more than I anticipated. Thank you all!
For inquiring minds... I didn't do it myself this first time. I had the engine serviced at a yard.
I know... I cheated and took the easy way out. But at least I know it was done correctly and now have a new impeller in the water pump.

**Dockhead** · 03-10-2021, 05:41

Quote:

Originally Posted by noelex 77

The threaded versions are readilly availble (at least in Europe). They make the job much easier.

Absolutely. It's night and day compared to wrestling with a non-threaded one, especially with these engines where the water pump">raw water pump backs up against the starter

At least I have direct access to mine through my heads; I feel really sorry for the guys who have to do a reach-around from the front. I can understand why they would want to just remove the whole pump.