I am heading back down to St. John in early March to tackle some maintenance
on the engine
in our 1981 Stevens 47.
is a Yanmar
4JH2HTE. 75hp turbo diesel
with approximately 3800 hours on it.
This engine was installed in 1992. She runs well, but does blow a bit of whitish smoke.
I really do not know what to think of this whitish - light grey smoke. It is not excessive and is present more when the boat is cold than when fully warmed up but even when warm it does do this smoke a bit. I suspected compression
, and I guess it could be, but the engine does start immediately when cranked even when cold. By immediately, I mean that when the key is turned the engine turns over no more than for 1 or 2 seconds before firing and running smoothly. Its probably just condensation
.... but I am a worry wart.
Regardless, the engine definitely needs a valve adjustment. Also, a number of the rubber hoses on the engine are showing dry rot
and need to be replaced. The engine itself has a fair amount of surface rust that needs to be ground off, treated and then repainted.
My plan is to strip off as many hoses and ancillaries as possible (including the starter, alternator
, most wiring
and most hoses and such) so I can get at the entire engine. I will then sand and grind off all the surface rust, clean everything thoroughly, treat the metal and repaint it all. Then after adjusting the valves and doing any other maintenance
required I will put it all back together again with new hoses and gaskets and anything else required. I will also be replacing any worn wiring
and worn connectors.
should I replace? Where is a good place to source such parts
? I have never adjusted the valves on a Yanmar diesel
... but I have on lots of pushrod activated overhead valve cars, my understanding is that the Yanmar uses screw adjusters so how hard can it be?
Any Yanmar techs on the board? I though I read on here once that a good Yanmar tech posted frequently who is here near Lake Lanier in GA but I cannot find the posts after searching...
We will be bringing my boat back from St. John to Savannah, GA in May so I need to make sure the engine is in top shape before the trip. All tips and suggestions are greatly appreciated. I did just change the oil
, filter and fuel
filters in December when last on the boat.