Re: Yanmar 100HP Fuel Pump maintenance-free?

Craig Briggs

Hi Francesco,

I think you may be asking more of a philosophy question than an engine maintenance one :-)  

Then again, nothing is maintenance-free forever. There are some signs of overhaul being needed, though. My Perkins developed an unstable rpm at about 4000 hours and I had the pump rebuilt, since I was rebuilding the rest of the engine myself anyway. (The injection pump is not a DIY job.) The shop reported that there was a good deal of internal corrosion from water having entered the system (a prior owner, I sure) and it would likely soon have resulted in a run-away situation with a failed governor. 

I'm now up to 7500 hours and it seems fine. With the pristine way you keep Peregrinus I would assert you're nowhere near a (costly) overhaul of the pump,

Cheers,  Craig SN#68

---In amelyachtowners@..., <svperegrinus@...> wrote :


Looking at the Yanmar "Operation Manual", there is no mention of maintenance of the fuel pump, nor of any maintenance adjustment.

In the "Periodic Checking List" page of the Yanmar "Service Manual", there is no mention of maintenance of the fuel pump, nor of any maintenance adjustment.

However, in the Yanmar "Service Manual", there is a section called "Overhaul", and it says the fuel pump should be sent to a ZEXEL (the manufacturer of the pump) service center, and there are several pages of parameters and maintenance items for the fuel pump.

So, it seems the fuel pump is a maintenance-free item, except when you overhaul the engine.  Is this correct?  Is there any preventive maintenance for it, or is this a sort of a live and let die kind of component?

Thanks in advance,


3,400 hours on 4JH3-HTE engine

Fethiye, ancient Telmessos, Asia Minor

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