Yanmar 4JH3 -- Anyone Know How to Remove the Injection Pump

[Dockhead]

We are stumped -- it seems to have a retaining ring or clip somewhere which we can't find. The manual doesn't say a word about removing or replacing the injection pump. Anyone have any experience with this?

[TheOffice]

this might help:
Yanmar: Qm Gm hm 4jh 4jh2 Repair Manual Yanmar 1975 1998 Repair Manual, Covers All Qm, Gm/hm, 4jh And 4jh2 Series Engines And Transmissions'

[Dockhead]

Originally Posted by TheOffice

this might help:
Yanmar: Qm Gm hm 4jh 4jh2 Repair Manual Yanmar 1975 1998 Repair Manual, Covers All Qm, Gm/hm, 4jh And 4jh2 Series Engines And Transmissions'

Thanks -- that's 4JH2, however, which is a rather different engine. Do you happen to know whether there's one of these for the 4JH3? I have the factory service/overhaul manual, but it doesn't say a word about getting the pump on and off.

[TheOffice]

try this:
http://www.sv-zanshin.com/manuals/ya...3-te2001_9.pdf

[Dockhead]

Thanks again. That's the factory manual which I have. I wish Haynes did marine engines

[hpeer]

Three months ago I changed an injector pump on a 4 JH4, not sure if they are similar. I th ink they are.

There is a thread here on that painful experience.

I don't know about there being a retaining clip. I had three studs with nuts, one of which was impossible to get a wrench on. Used a big screwdriver and hammer to move the nut. Not pretty.

Here is a word of advice not related to your question. If your engi he is like mine, and I think it is, you need to carefully mark the gears before removing the pump and then be careful to not rotate the engine. there is an idler gear between the crank shaft drive gear and the pump gear. If you loose the relationship between th see three you loose your timing.

To your question, look for three nuts holding the pump to the forward housing. There is Lso a bracket under the pump holding it, that is not obvious.

Then some other stuff had to be moved, or at least relaxed, to allow reward movement.

It was not easy and clearly not designed for field maintenance.

Good luck.

I'm on an I pad and can't find my earlier post back in late May.

[DeepFrz]

http://www.cruisersforum.com/forums/...evs-82753.html

[Dockhead]

Thanks, extremely useful!!

And what it more, your problem sounds just like mine -- the engine won't rev. Here is the thread on it: http://www.cruisersforum.com/forums/...ems-85635.html

Since it won't rev even in neutral, I didn't think it could be fuel system problems. But yours did the same thing. Unlike you, I don't have anything in the filters. But now you've given me pause . . .