New engine

[bcguy]

I have been running my new Isuzu LE1 4 cyl 54 hp for the past month without high rpms. Yesterday against heavy winds and tide I had to run it to near max for 30 minutes. All guages operated normally and no warning buzzers went off. The engine was hot and I noticed an acrid smell and some smoke haze (not thick or smoking like a fire). I am just assuming that given the high temperature of the engine's first hard running it was just the new paint perhaps?

... thanks

[twistedtree]

That's probably it, but how hot is hot? Does your temp gauge give an actual number? The important thing is to be sure the engine isn't over loaded by being over propped. At full throttle, then engine should reach full rated RPM, preferably a little more (say 5%) more. You should confirm that and re-prop if necessary. Overloading a diesel can significantly shorten it's life.

Oh, and another thing to confirm is that the exhaust is being properly cooled. An infrared thermometer is a quick way to check the surface temp to look for hot spots.

[delmarrey]

Originally Posted by bcguy

The engine was hot and I noticed an acrid smell and some smoke haze (not thick or smoking like a fire). I am just assuming that given the high temperature of the engine's first hard running it was just the new paint perhaps?

... thanks

More then likely! If the water temp stayed normal and no oil was forced out you should be fine. A brake in of a Yanmar is 75% of max for the forst 50 hours.

I use a suction blower for my engine room when running long and hard. It helps to keep it cooler. The suction hose is right over the tranny. Extracts the smells too, to keep them from going in the boat.