Replacement of engine

[henric]

Hi,

I am a owner of Hunter Passage 456 in Sweden. Hopefully I never have to replace the engine (4JH3-TE) since it seems really difficult to remove it (and get the new one in place). But I wonder if there is any owner of a 456 Passage in this forum that has done it? All operations at the engine like changing impeller is difficult regarding to me because of the non space. I'm just curious if its just me wondering about this?

Best regards
Henric

 

[sail sfbay]

Photos of what you want to access? Based on my experience with a 386 and 46 access to engine components, like water pump, can be facilated by installing inspection port or disconnect the transmission, remove motor mounts and alternator and jack up the engine (that is what I had to do on my 386 to replace water pump). Of course, I am awways amazed at how Yanmar engine mechanics can acess engine components.

 

[SycloneDriver]

It seems like some of the impellers on certain Yanmar/Hunters are very difficult to change. I think I saw a kit that made the process much simper. If remember correctly one of our forum members was billed $950 to have the impeller changed, seemed like robbery until I did a little research.

 

[artboas]

It seems like some of the impellers on certain Yanmar/Hunters are very difficult to change. I think I saw a kit the made the process much simper. If remember correctly one of our forum members was billed $950 to have the impeller changed, seemed like robbery until I did a little research.

The 10 minute impeller change modification was my post about 3 years ago. It was a horrible Yanmar design, which makes it impossible to change the impeller unless you’re at a dock with 3 hours to spare
I strongly suggest going through this post and modifying your engine.
I literally stopped cruising because of this impeller problem. On the overnight passage to the 1000 islands you go though a very dangerous rocky shoal area where winds are severe. I just couldn’t deal with the risk.
And owing to health issues, i personally can’t lie on top of an engine for 30 minutes at a stretch (which is what it takes ti change the impeller)
The mechanic who quoted $950 to change it was under-charging . It’s a miserable job.

 

[Georgedoyle]

I just discovered while changing my engine mounts that you can’t remove the raw water pump without first removing the motor mount. I already knew that the alternator would have to be removed. It looks like our pump needs a new seal. That’s a lot of work to go through to service the pump.

 

[henric]

Thanks all, I will read the post about the impeller modification, it seems like a good investment. It took a while and I also discovered it was never changed (2005-2021). But what I really was thinking about if its possible to to remove and replace the whole engine. If its ever been done? I really hope I never have to do it cause its seems like its built in. In my earlier Bavaria I almost could walk around the engine.

 

[artboas]

I just discovered while changing my engine mounts that you can’t remove the raw water pump without first removing the motor mount. I already knew that the alternator would have to be removed. It looks like our pump needs a new seal. That’s a lot of work to go through to service the pump.

You are 100% correct. This is noted in my “10 minute impeller change” post.
This must be done to perform the modification, and install the blanking plate.
From then on, changing your impeller is a very simple matter.

 

[Georgedoyle]

I have figured out process for changing the impeller relatively quickly as is. It takes about 30 minutes at the dock. It’s not really feasible in any kind of rough seas. Changing the actual raw water pump or even removing it for service is another story. I might have to go with your reconfiguration plan eventually. But that's a project as well.

 

[artboas]

I have figured out process for changing the impeller relatively quickly as is. It takes about 30 minutes at the dock. It’s not really feasible in any kind of rough seas. Changing the actual raw water pump or even removing it for service is another story. I might have to go with your reconfiguration plan eventually. But that's a project as well.

I can’t imagine how you change this in 30 minutes. Before I did the mod, I spoke to many mechanics. Some pulled the intercooler, others did the alternator. All of them quoted it at a 2-3 hour job, and hated doing it.
I worked with a pro to help me with the upgrade. The reason for that was I wasn’t comfortable with pulling the engine mount myself.
We had the whole upgrade done in 4 hours… and that was figuring it out from scratch.
So, it’s less than a day’s work.
If your impeller goes with your boat off the dock, it’s a tow back in.
I put off cruising to the 1000 islands until I had this figured out. Couldn’t deal with the risk.