Requests for tips to remove impeller on 4JH Yanmar

[Shrew]

Originally Posted by sailorboy1

Last impeller I got this past summer came as a kit with the o-ring and SS bolts with hex heads instead of the screw head

I have ss hex head bolts on my pump. I still need to use a universal joint. There is no way I could get a screwdriver and my fist on the inside bolt.

[MicHughV]

These are faster. Use a scuba tank if you don't have compressed air. I suppose you could modify an oscillating tool blade to work
ahttps://www.northerntool.com/shop/to...9&gclsrc=3p.ds

cool looking gadget....something I'd like to have in my arsenal of tools...
tnx...

[skipperpete]

The starter motor really blocks any attempt to use a dremel, hacksaw blade or even the jabsco puller (which will fit...barely). All of these methods will work but the pain of lying on the cabin floor and reaching into the limited space to extract the impeller hub could be lessened by removing the front engine mount and water pump">raw water pump and fixing it on the bench. Avoid at all costs damaging the oring groove, if enough of it is broken the only safe options are the use of a gasket or a new pump housing

[JSurr]

Thanx for all the advise of installing the Yanmar OEM impeller with the threaded removing tool. It is something to consider once I am able to remove the existing impeller. I have to get the existing impeller off the post before I am able to consider what I will put in its place

[jamhass]

Different engine, but I found a (very) slight bit of silicone grease on the splines during reinstallation makes it a bit easier next time.

[Scubaseas]

Originally Posted by MicHughV

These are faster. Use a scuba tank if you don't have compressed air. I suppose you could modify an oscillating tool blade to work
https://www.northerntool.com/shop/to...9&gclsrc=3p.ds

cool looking gadget....something I'd like to have in my arsenal of tools...
tnx...

Works surprisingly well at cutting sheet metal. Excellent tool for manifold nuts. Or seized fittings/bushings/bearings/etc..Very little vibration too.

[SaltyMetals]

I have a Yanmar 4JH3 on a 2004 Jeanneau 43ds where the impeller faces backwards and is a nightmare to replace since it is almost impossible to SEE it. Has to be done by feel. I think that later versions of the 4JH had sorted this problem such that the impeller faces forwards and is therefore much easier to get at.


Think the original message showed the impeller which looks like it was mounted back-to-front so that the threaded portion in the hub of the impeller is on the inside instead of the outside where it should be. So the Yanmar extractor would not solve this prblm. I have the Jabsco two-lever puller which has a tightening mechanism to really squeeze the two sharp points of the puller hard against the rubber central area. Yes it works ok, every time but such a struggle on my engine since i cannot see what i am doing, only do it by feel. The engineers who designed this model of engine such that the impeller faces backwards should have been thrown over-board!



A note of interest for pcmm @ #20: I also recently bought a spare impeller which still has the threaded part on one side so that the Yanmar extractor can be used. This was from a UK supplier who is a Yanmar agent on the Hamble River, Nr Southampton (parts@marine-power.co.uk )


Andrew
"Genial Bee"

[malbert73]

I found the easiest way to replace the impeller on my 4JHE was to loosen all engine mounts and install this easier to service system:

https://betamarineengines.com/index....ngines/beta-50

[emoji6]

[noelex 77]

Originally Posted by SaltyMetals

The engineers who designed this model of engine such that the impeller faces backwards should have been thrown over-board!

I would throw over board the boat builder who installs this engine without providing access to the port side.

[SaltyMetals]

Noelex,


Access on my boat is fine. Prblm is that the impeller is partially hidden under the alternator and tucked away behind the starter motor. A nightmare!
Andrew

[Bluechart]

I just went through this, had to remove the motor mount bracket. But I’m glad I did. It’s a tight work space,,,,,

I removed the top motor mount nut, then I used a LiftMaster Wide Deck Motorcycle Center Scissor Lift Jack Hoist Stand under the oil pan and plywood to gently lift the engine, when the engine raised 1/16” I stopped lifting.

Then I removed the motor mount bracket that attaches to the engine block. (I did not remove the motor mount.)
It took a small pile of extensions and socket swivels to remove the motor mount bracket and water pump.

But it was worth the work, I was able to clean and prime/paint the block and bracket (rust from leaking water pump) replace the water pump, and align the shaft when I was done.

[noelex 77]

Originally Posted by SaltyMetals

Noelex,
Access on my boat is fine.

I would still not be happy with a boatbuilder who installed an engine with an impeller that could not be seen and had to be changed by feel.

There is no need for this if a suitable access hatch is installed.

[Bluechart]

Unfortunately, Yanmar created this problem with an aft facing water pump (behind the motor mount).. On later versions of this engine, Yanmar used a forward facing pump, problem solved.

[CrispyCringle]

Originally Posted by Scubaseas

two flat blade screw drivers. 180* opposite. Push into impeller and push down equally at the same time. Careful not to deform where the o-ring goes. All you need to do is to get it "rocking" on the shaft and it'll pull right up. ......

This is what I had to use to get my stuck impeller out on the Yammy. Two short flat blades. Dig into the rubber surrounding the shaft and pry them 'up'. A drop or so if penetrating oil on the splines may help as well.

Good luck. So annoying when simple tasks are so hard to do.

[sailcrazy]

We have a 4JH-TE, 1989, and the port side is pretty well buried/non-accessable on our boat. We do have front and stbd access. We need to go at it from the front, remove the altrntr and the raw water supply hose, and then work blind and backward to remove the entire pump. Once out, we have good access to the face and pump. A real PITA! Getting the impeller out of the pump is a matter of prying in side/side, until it lets go., and then reversing the whole process. Ours does not have the threaded end, it just slips onto the flat-sided shaft.