What is the lower 3" bellow for?

[b4tn]

Putting in today started seeing smoke. Being an off-road enthusiast it smelled like steam from water on a hot exhaust. After we pulled out I took a look and the very lowest bellow on the out drive had come loose. It's still in good shape and the hose clamp is still there. Is this an exhaust? Should I look forward to any other damage? Any tips for keeping it on? It's a bravo iii outdrive

 

[Scott Danforth]

from top to bottom. u-joint bellows, Shift bellows, Exhaust Bellows

if this is a new to you boat, you should remove the drive, inspect the alignment and gimble bearing and replace the bellows anyway. they are a bi-annual maintenance item.

 

[MarkSee]

You don't mention what year the drive or engine but check out this link on the right hand page where you can see item #14 is the exhaust bellow however some setups (like mine) simply use an exhaust 'tube' (item 15) that only connects on the transom side anyway.
Makes for a slightly louder sound.

http://boatinfo.no/lib/mercruiser/manuals/mercruiser28.html#/310

Mark

 

[tpenfield]

I replace the exhaust bellow with the exhaust tube (since I have Bravo as well) You might want to do the same. . . it seems like the exhaust bellows are hard to keep attached on the Bravo's.

 

[poconojoe]

As said, exhaust bellows coming loose is no biggie. Won't damage anything. The exhaust is normally directed down and out near the propeller. If your exhaust bellows came disconnect on one side, your exhaust will just exit there. Some say it will be a bit louder that way. Mine came lose a couple years ago and I just left it. Some replace the bellows with an exhaust tube which only connects on one side.

 

[H20Rat]

from top to bottom. u-joint bellows, Shift bellows, Exhaust Bellows

if this is a new to you boat, you should remove the drive, inspect the alignment and gimble bearing and replace the bellows anyway. they are a bi-annual maintenance item.

Assuming you meant biennial (every other year), but in any case, you really replace your bellows that frequently? Depends on your usage and environment, but at least up north, I get 10-15 years (or more) on all those mentioned parts. Being able to store it with the drive down makes a huge difference. Merc's official answer is inspect every 100 hours, no mention of replacement based on time, only based on inspection.

 

[hoowahfun]

I would maybe look into whether or not it's an issue to leave the exhaust bellows loose from an exhaust back pressure perspective.

 

[Scott Danforth]

Volvo's manual is every 2 years for bellows. since the u-joints are an biennual inspection for both Volvo and Mercruiser and gear lube changes are every 100 hours or annual, your pulling the drive every year anyway. dont forget to pull the props and grease the shafts every 2 months (4 months in fresh water - Manual 39, page IB-4)

 

[b4tn]

Thanks all. The boat is new to me all bellows, gimbal, and maintenance was done prior to being sold to be about 2 months ago. However, I have had so many issues. I had to replace the ignition coil, then I killed the starter and had to replace that. Being a self made mechanic I do all my own work and feel like I am working on it more than enjoying it. Just yesterday I had to replace a hub on the trailer before we launched lol glad that this is a no brainer

 

[Scott Danforth]

and feel like I am working on it more than enjoying it.

we have years like that.....lol. seriously once you get everything straightened out, use the boat often and enjoy it. the amount of maintenance per calendar year does not change, however if you get out and use the boat as often as possible, the ratio comes out in your favor.

 

[scott8058]

I just had the exhaust bellow on mine replaced this year and i can't keep the thing stuck on, its like it is to short to reach. We tried the adhesive and clamp but still comes off one side. I think i am just going to get the exhaust tube also, but will it hurt if i run it a few times with no exhaust bellow? I first noticed it was off bc it sounded a little different at the dock. Didn't notice much change when up on plane but def do on the muffs and when idling. Thanks for the help

 

[b4tn]

I was out yesterday for about 6 hours and feel like when it's disconnected I take on a lot of water. It might be a separate issue but when I pulled the plug it drained heavy for a solid minute or two.

 

[bheff]

Assuming you meant biennial (every other year), but in any case, you really replace your bellows that frequently? Depends on your usage and environment, but at least up north, I get 10-15 years (or more) on all those mentioned parts. Being able to store it with the drive down makes a huge difference. Merc's official answer is inspect every 100 hours, no mention of replacement based on time, only based on inspection.

​I cant be 100% for sure, but Ill bet mine are pushing the 15 year age. They still look good, but I'm going to replace this fall when I pull the outdrive to inspect it. Its 42 years old and I want it to run another 42.