I definitely did not mean to imply that 4000 hrs is a good time for an overhaul. I think that if your engine is running well that is way too early - like by a factor of 2 or 3. In my case it was only needed because water had gotten into the fuel and corroded internal parts of the pump. Actually I was rebuilding the engine because a lifting rod had bent and I figured I'd have the injection pump overhauled since I had everything apart anyway and was suspicious about the rpm surge - good thing I did.
So I'd strongly disagree that 4000 is any kind of an engine overhaul horizon. It really depends on how well you "hug" your engine along the way to maintain it and if some random early failure occurs. I see no reason not to expect 10,000 +++ hours. Greyhound buses go a few million miles on their diesels, with periodic rebuilds.
That being said, another criterion may be the years on your engine. My engine has averaged 300 hours a year and I've reached 7500 in 25 years (1992 boat). I wouldn't argue with someone who felt, say, 15 to 20 years is a good time to have a shop overhaul the injection pump (and injectors), even if they had done far fewer hours. There's always a little moisture in the fuel and the inside of the pump and gaskets are subject to corrosion and aging.
So keep hugging your engine and 'don worry, mon!
---In amelyachtowners@..., <svperegrinus@...> wrote :
Hello Bill and Craig,
Yes, the question is about the fuel injection pump. On the Yanmar, it is a ZEXEL NP - VE - 4 / 12 F 1900 R NP1995.
Craig, interesting that you had the pump rebuilt at 4,000 hrs... we are not there yet, and at our current average, will reach 4,000 hrs in about 2 years. Just like you had the pump rebuilt at engine overhaul time, the Yanmar manual seems to implicate that the pump is to be overhauled at the same time as the engine itself...
... so along these lines... is 4,000 hrs perhaps the horizon for an engine overhaul on an Amel... ???
Yeah, kind of a philosophical question!
SM2K N. 350 (2002)