ENGINE BLOW BY ?

Hi,

I have a Yanmar 4JH4AE with 740 hours on it. I bought the boat with 520 hours on it.

Max rpm is 3000, I had been cruising at 2000 but I keep hearing faster is better so
I began cruising at 2600. After several hours at 2600 I can smell a little burning oil inside
the boat. I checked the engine and found a little oil on the outside of the air intake manifold, along
the bottom edge of the cover plate. I can also smell a little burning oil in the exhaust from time to time
but I can't see any smoke. There is no noticeable consumption on the dip stick.

Is this engine blow by ? Is this normal ?

Thanks,

Jules

Thanks Hayden !

Hi Hayden, I’m replaying to this old post because i’m experiencing the same problem on my 1999 350.
I’m gomma to reduce the level of the oil from 3/4 to mid point but in the meanwhile i opened the air intake to be sure that air filter is clean and not clogged.
Inside the air intake I just found a not removable metal net (see picture)…Is this the filter or just the filter housing?

Thanks in advance for your help

Giuseppe