Engine maintenance - what do you actually perform?

[pilott]

Just so the OP doesn't worry - I believe that the Yanmar 4JH series does not feature engine zincs.
I know my 4JHE doesn't.

[Flod]

I change the propahaft zinc. As stated I the previous reply I haven’t seen anything about engine zincs. Regarding the fuel filters I will get around to that. This is definitely one thing I know how to do. Had a diesel bug stirred up and clogged all filters in a previous boat (yanmar 3Ym30) and I had to change all filters, empty and clean tank, install inspection hole (I learned it’s hard to penetrate stainless steel), install separate day tank with 3 way valve and install sludge/water drain in the bottom of the tank. All of this was no fun at all and Left the whole boat stink of diesel. I guess this is why I don’t touch the current fuel system if I don’t have to.

[Lambretta]

Originally Posted by Flod

Thanks for the replies. I have one of these pumps to do the oil change. https://www.amazon.com/Mercury-Preci.../dp/B001QFEVNA
It hooks up to the dipstick hole and makes engine oil change easy. Have to buy one with a tube to do the gear oil change I guess.
My engine have low hours. I think it have 650hrs (2003 model) and runs fine. I have had older Yanmars and Volvos before and they required more to keep on going

A heads up on using these vacuum oil pumps ...... I was with the Yanmar service manager who did the warranty service on my Yanmars recently ...... he strongly recommends that when using one of these oil extraction pumps that you open the oil filler cap on top of the engine as the pressure from these pumps can sometimes damage the engine seals due to the vacuum force they can create.

Another heads up ...... only use good quality engine coolant and you only need to change it every two years and lastly ...... do NOT mix different coolants ..... they potentially have different boiling points etc and can give rise to serious problems

[Flod]

I always open the top cap before starting to pump. I would expect it to be very hard otherwise do to the back pressure.

I read another thread on the coolant and different kinds and I believe to have control over this.

Today I got tired of servicing the toilet pump and replaced the whole thing. A new one inc pump was 120 euro, a new pump was 110 euro and service set 70 euro.

[Gary Mc]

It is my understanding, on Yanmars at least, that if you have a heat exchanger you will not have an engine zinc. If it is raw water cooled you will and therefore have to check it occasionally.

[Pete7]

I prefer to use one of these which will hold the oil from the engine and gearbox before needing emptying:

https://www.amazon.com/Hydro-Turf-Oi...s%2C226&sr=8-1

Or if the $$$ aren't an issue then these are super and used on a previous boat with a big 4.2L Ford.

https://www.amazon.com/gp/offer-list...8161713&sr=8-8

[winschwab]

I see that your model Yanmar does not have zincs (the majority do). On my Westerbeke engine the zinc is in the heat exchanger. Shortly after I bought the boat the heat exchanger failed (corrosion ate a hole in the casing). The zinc was completely gone for who knows how long.

More on engine zincs:

https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAE

"Zinc pencils
Heat exchangers, because they are typically a copper alloy, are at risk of galvanic corrosion. To combat this, many heat exchangers are fitted with a zinc "pencil" anode. You will find it (or not) under a brass plug in the exchanger. The pencil is unscrewed from the plug for replacement. Some engines have a similar zinc pencil inside the cooling-water jacket to protect dissimilar metals in the engine. Determine if your engine and heat exchanger are fitted with internal anodes, and if so, check them at least annually. If they are half depleted. . .well, you know."