Help needed: Very noisy mercruiser sterndrive

[oxonthebox]

Please can someone help me. I recently bought a SeaRay 210 Sundeck. It was great in the sea trials. Since then I have had new risers installed and the outdrive serviced. Now it runs great BUT it sounds like a cigarette boat. The noise is from the exhaust at the stern drive not the engine. The engine runs great. I had a look today and I see the exhaust bubbling out at the top of the stern drive. I thought the exhaust was pushed through the propellor. Is there something wrong with the stern drive? did my mechanic break or forget some kind of boot or something? Thank you.

 

[zbnutcase]

Re: Help needed: Very noisy mercruiser sterndrive

He may have replaced the exhaust bellows with the available exhaust tube, which will let more exhaust out up closer to the waterline.

 

[jtmarten]

Re: Help needed: Very noisy mercruiser sterndrive

Exhaust tubes are *slightly* louder than exhaust bellows, certainly nowhere near as loud as thru-hull.
At idle, the exhaust will come out the transom plate side ports.
If you have a tube installed instead of the bellows, with the drive trimmed down it should be no different than a bellows. Once the drive is trimmed up, it will be slightly louder.

Are you sure your mechanic installed the risers correctly? Exhaust flowing plenty of water?

 

[jtmarten]

Re: Help needed: Very noisy mercruiser sterndrive

He may have replaced the exhaust bellows with the available exhaust tube, which will let more exhaust out up closer to the waterline.

Incorrect. The tube is at the lowest level of the exhaust system. At prop level when the drive is down.
Technically, when the bellows is installed, and the drive trimmed up, the exhaust is closer to the waterline.

 

[oxonthebox]

Re: Help needed: Very noisy mercruiser sterndrive

see next post

 

[oxonthebox]

Re: Help needed: Very noisy mercruiser sterndrive

Exhaust tubes are *slightly* louder than exhaust bellows, certainly nowhere near as loud as thru-hull.
At idle, the exhaust will come out the transom plate side ports.
If you have a tube installed instead of the bellows, with the drive trimmed down it should be no different than a bellows. Once the drive is trimmed up, it will be slightly louder.

Are you sure your mechanic installed the risers correctly? Exhaust flowing plenty of water?

Are you sure your mechanic installed the risers correctly? Exhaust flowing plenty of water?

I assume I could only see this by getting the boat out of the water and running it through on land.

The boat runs at about 170 per the temp guage. do you think that's healthy?

 

[jtmarten]

Re: Help needed: Very noisy mercruiser sterndrive

Sounds like a good temp.
Could be everything is fine. Have you checked to see if he installed bellows or a tube? Or called to ask?
If the drive is trimmed up at idle, you may just be hearing the exhaust bubbling. Try it with the drive trimmed down, see if there is a difference.

 

[oxonthebox]

Re: Help needed: Very noisy mercruiser sterndrive

Thank you for the help. I have tried with engine trimmed up and down. No difference. the boat sounds like the engine is up all the time. I am going to ask him about the bellows or tube? I will try and get someone to check it out

thanks