Marinette Boat Forum

I'm getting a fairly noticeable burning smell any time I exceed about 1500rpm. I'm not seeing any smoke or finding any melting hoses. The engine does really does not seem to leak oil anywhere but maybe I'm just looking in the wrong places...

Ideas? No smell at all below approx 1500 rpm

Belts? Wiring?
Also, how/where are you actually checking temps? Have you tried one of those fairly inexpensive but accurate laser temp readers? They do a quick job of checking in lots of places.

Does it smell like plastic/rubber, hot oil or electrical?

Do you smell it at the helm, maybe from the exhaust or do you smell it when you open the engine hatches? Does it smell inside the engine room or just outside the boat?

If a belt(s) is slipping you may be able to feel or see black rubber residue on the belt or inline with the belt rotation. Make sure engine is off and secure before inspecting belts.

-karl

Thanks for the ideas so far...I will check out the belts next time I'm at the boat. I installed a new one-wire alternator earlier this season and have periodically been checking on it so I will take another look at how that's doing.

I am at the helm station when I notice the smell. Pretty sure it's not exhaust. Definitely coming from engine compartment. Can smell it with the hatches closed. (my hatches are very worn out, rotted around the edges, etc.)

To me, it seems like a burning oil or rubber smell.

A few weeks ago, I borrowed a laser temp sensor and the measured temps of about 140 in various places on the block. Exhaust manifolds in the 90s.

Might be time to buy my own laser for more extensive testing.

I'm betting on the Chinese alternator. One of mine lasted about 30 hours engine time. A little my fault, because I run my deep cycle battery down jamming tunes all the time. Need a larger battery bank and or a higher amp alternator. The alternator overheats if it has to charge a dead battery all the time.
Watch for your engine to die and hope your parallel switch works.

My alternator is a one wire made by ARCO...supposedly made in USA

The alt. does seem to run a little hot though...