I have an  15 hp Yamaha outboard that is only a few years old.

I used it on Friday with no problem.

After towing to a new location, the motor cranked very loud on Saturday.

Motor is running great, but sounds like it has no muffler  :'(.  It reminds me of when you crank an outboard out of the water.

I took the cowling off looking for something loose, but can find nothing.

The motor is so clean, it look brand new.

Any ideas or suggestions of what I can do to see what is wrong?

Thanks in advance!!!

This may have nothing to do with it, but definitely worth checking out.  You say it sound slike it is out of the water.  Have you checked to b e sure the water(coolant) is circulating to cool the motoe.  Check for any obstructions in the water intake.  There also might be something loose on the motor, ie muffler, header????

But I am no mechanic, but  I would defintiely check these out.

Don't know crap about Yammy's but for you to get that on any motor, the exhaust gas has to be exiting the motor above the water line instead of through the prop.  Make sure your lower unit is not loose and letting the exhuast come out between the LU and mid section.   If that's good and you see nothing visual that will let the exhaust escape you might have blown  a powerhead gasket between the power head and the mid section.  If it has blow this gasket, don't run it anymore until you have it repaired.

Don't know crap about Yammy's but for you to get that on any motor, the exhaust gas has to be exiting the motor above the water line instead of through the prop. Make sure your lower unit is not loose and letting the exhuast come out between the LU and mid section. If that's good and you see nothing visual that will let the exhaust escape you might have blown a powerhead gasket between the power head and the mid section. If it has blow this gasket, don't run it anymore until you have it repaired.

I had this exact thing happen to my mariner. Unfortunately it was in the middle of a two week vacation in Canada. Fortunately the marina I took it two had it fixed it two days. The symptoms where loud exhaust and water coming out of the cowling. I took the cowling off to investigate and the block was actually loose on its mounting. Check to see if this is true on yours. Note: My mariner was made by Yamaha.

Paul

Thanks for the feedback.

I looked under the cowling and could not find anything loose.

Dropped it off today with a repair shop.

The mechanic made me feel confident, stating that it couldn't be much because there is not much there.

Keeping my fingers crossed and hoping for the best.

The motor probally doesn't have 5 tanks of fuel run through it.

Will update when fixed.