Do you follow the recommended maintenance schedule?

[AndyBC]

I'm in the process of winterizing my boat, and just curious if you all religiously follow the maintenance schedule or are there some things that you haven't changed in a long time because you've inspected and it looks fine?

This is my second season with the boat (100 hrs last season, 50 hrs this season, 1700 hrs total), and here are a few maintenance things I've done:
-Air filter: I cleaned it this season (manual recommends 100 hrs or annual)
-Oil and filter change: I've changed annually (manual recommends 250 hrs or annual)
-Transmission fluid: I didn't change last season, but plan to change this weekend (manual recommends 250 hrs or annual)
-Primary & secondary fuel filters: I changed both last weekend, but not last season (manual recommends 250 hrs or annual)
-Coolant: the PO drained, flushed and refilled in 2022.  I didn't do so last season or this season, plan to do so in the spring (manual recommends 500 hrs or annual)
-Raw water pump impeller: I didn't change last season but changed at the beginning of this season and plan to remove and inspect this weekend and leave it out for the winter (manual recommends inspect every 500 hrs or annual)

Also, while inspecting my fuel lift pump I see that it says Gasoline (see photo).  I don't know if this was a mistake from the factory, or if a PO replaced with the incorrect part.  It looks like it has been there for a long time though.  The engine always starts up within 1 second (I hear the pump working when I engage the glow plugs) and appears to run just fine.  Any reason why I should change it to the correct Diesel lift pump?  Do the 2 types of pumps have significant differences, such as fuel flow rate?

[robbjd]

Our 97 34MkII had a much different lift pump. The"diesel" version of your pump is #39275 @ $258 USD. Our lift pump did fail @ ~1500 hrs. I replaced it with an aftermarket pump (Carquest 41502 Cylindrical Fuel Pump Kit 12V, 6.5-8PSI 24in Min Dry Lift, 32 GPH) for $80 USD. Ours is a single wire pump, yours two wire. The Facet pumps are compatible with both gas & diesel.

https://facet-purolator.com/pumps/

John

[Jim Hardesty]

Any reason why I should change it to the correct Diesel lift pump?

My thought is "if it's not broke don't fix it".  As has been mentioned here before the fuel tank is above the engine creating low demands on the pump. I don't carry a spare.  I do have a list, from here, of replacement pumps.  If I had to replace the pump on a cruise, I believe that it would be easy enough to get a replacement from an auto parts store or tractor supply.
As for following the recommended maintenance schedule. I do, and always redo at the end of the season even if maintenance was done during the season.  I could be mistaken, but I like storing with fresh clean fluids.  One exception is fuel filters,  I change them as required or at the start of a long cruise.  As required meaning the engine fails to reach full RPM.
Jim

[AndyBC]

Thanks John and Jim for your feedback!  I think I'll leave well enough alone until it comes time for replacement.

Jim, sounds like you are very diligent with maintenance!  So you change both fuel filters as soon as you notice that the engine doesn't reach max RPM, or just one of the filters?  What is your set up?  My primary is 15 microns nominal, and I assume the secondary (engine) is 10 microns nominal.

[Jim Hardesty]

So you change both fuel filters as soon as you notice that the engine doesn't reach max RPM, or just one of the filters?  What is your set up?  My primary is 15 microns nominal, and I assume the secondary (engine) is 10 microns nominal.

My primary is Racor R15s if my alleged memory is correct that's 10 microns the spin-on secondary isn't as fine I believe.  In the past I've tried only changing only the primary and still had to change the secondary.  For reasons I don't understand.  So I just change both.  First the primary, run the engine, then the secondary.  Bleeding as necessary.
Jim

[Ron Hill]

Andy : I've got a M25XPB which is a 3 cylinder "M35" and here's what I do:
Air Filter - I clean it and reoil it every 5 years or so. The engine compartment is a clean environment!!
Oil and Filter - I use the diesel Mobile 1 oil and change it and the filter every 100 hrs or end of every season (store it with clean oil)!!
Fuel filter - I change the Racor every spring. Because I use a 2 micron Racor I only change the engine fuel filter every 5 years to 7 years
Coolant : I change that every 5 - 7 years. If the recovery bottle shows low I add some water pump lube to it!! (that lube also has rust inhibitor)
Raw water pump - I remove the impeller every fall (winter storage). I inspect and if OK reverse it for spring installation and reinstall in the spring.
Transmission - I fill it all the way for winter storage. In the spring I suck it all out and refill to proper level !!

I'd do as Jim suggested - "If it aint broke DON"T fix it"!!

[robbjd]

Andy, I also have a Racor R15S as my primary filter. This is a 2 micron filter which ensures that only nice clean, water free fuel passes through it. I've never found any contaminants in the internal filter of our lift pump. The secondary filter is a Universal 298854 (98% @ 25ų) which I changed when I had my lift pump failure 3 seasons ago. I just changed the Racor this morning and there was about 1/4 ounce of water in the bowl. We only burned 45 litres of diesel all season.

[AndyBC]

Thanks Ron, I appreciate you sharing your maintenance schedule!  Your air filter and coolant interval is definitely longer than what I see in the manual, but if this has worked for you all these years, then it means that you are definitely doing something right!!

Interesting that you and John both have 2 micron primary filters.  I may have to re-think about my setup.

John, do you change your Racor annually like Ron does?  Secondary filter changes every few years?

[robbjd]

Andy, I do change the Racor every year. I find that it traps water in the fuel, preventing it from getting to the lift pump, final filter, and injection pump. There is a fine mesh screen in the lift pump that will trap any particulate matter, but Its always clean when checked.
I also treat the fuel with fuel stabilizer when I top off the tank before haul out. Our boat has a K&N air filter that I inspect each season, clean, and oil if needed. I'm the fourth owner of this boat and the second owner utilized this message board often and upgraded many things on her.
John

https://www.knfilters.com/ru-2450-universal-clamp-on-air-filter