New Volvo Penta missing exhaust bellows

[mlbristow]

I recently purchased a new, zero time, 2000 Model year Glastron 185 GX with a 4.3l GL and SX outdrive. After breaking in the engine as per manufacturer guidelines, I noticed that the exhaust noise was louder than expected. I then traced the exhaust system and found that my lower unit was not equipped with a exhaust bellows and instead had only a short length of rubber hose that did not join to the lower unit, essentially an open pipe. I'm concerned that this not only increases the exhaust noise but could potentially be harmful to the engine via water backwash though the exhaust manifold. I plan on having the exhaust bellows installed but should I be concerned about damage? The engine has less the 20hrs total time.Thanks for your help.

 

[nickster]

Re: New Volvo Penta missing exhaust bellows

I can't answer your question on why your exhaust sounds louder. But I do know that the solid rubber hose that you see is your exhaust bellow and that the newer model boats do not connect with the lower unit i'm not shure why this is but when I get to work I will ask the inboard mechanic and will send another reply. But like I said your bellow does not connect with the lower unit.<br /><br />------------------

 

[nickster]

Re: New Volvo Penta missing exhaust bellows

The exhaust bellow that I had referred to earlier is there to cut down on the noise be shure when running your motr that the engine is trimmed all the way down and don't trailer your engine up while running only use the trim button the farther you take your motor up the louder the exhaust will be.<br /> Don't worry about the bellow being off the unit that is normal<br /><br />------------------

 

[alpapale]

Re: New Volvo Penta missing exhaust bellows

Nickster,<br /><br />I also have a 4.3 L Volvo-Penta GL I/O. I only have about 20 hours on it and I was surprised that the exhust sound does not seem to get as loud as my Johnson 115 O.B. did when I raised the prop out of the water. Are you saying that these new volvo's don't use through-the-hub exhaust? Maybe that explains my surprise.

 

[mlbristow]

Re: New Volvo Penta missing exhaust bellows

I sent a copy of my original posting to Volvo as well. They responded immediately and indicated that my configuration is standard for some "high performance" models and designed to reduce back pressure. They also indicated that I could receive a free "upgrade" under warranty and have the usual exhaust bellows installed. I've confirmed this with the local dealer and have the part on order. The upgrade applies to Volvo Penta units with specific Transom plate serial numbers (probably the ones without the bellows to begin with). I'm not sure how much difference the change will make either on noise or performance. Thanks for your suggestions.

 

[alpapale]

Re: New Volvo Penta missing exhaust bellows

I checked my exhaust again last night. It apperars to be coming from ports in the outdrive just above the cavitation plate, and not the prop. I don't see any "hose" though. Is it possible that there are so many differenct configurations?

 

[mlbristow]

Re: New Volvo Penta missing exhaust bellows

Your configuration is what I would consider standard. The exhaust ports are under the anticavitation plate, the exhaust is routed from the engine through the exhaust bellows and out through the exhaust ports. By adding the bellows to my boat I will have the same configuration. Check to see if you have two bellows present, the upper bellows contains the U joints and mechanical linkage, the lower bellows routes the exhaust.

 

[fishjumped]

Still cautious on the Exhaust back pressure problem I am having mine was so bad that it blew one end of it off at the hose clamp and transom plate connection of the bellows I inspected the system and there are no flappers in the y Tube or elbows only the 2 rubber flaps on the underside of the cavitation plate my set up is a 1994 Volvo Penta 7.4 with 290 DP

 

[GA_Boater]

Still cautious on the Exhaust back pressure problem I am having mine was so bad that it blew one end of it off at the hose clamp and transom plate connection of the bellows I inspected the system and there are no flappers in the y Tube or elbows only the 2 rubber flaps on the underside of the cavitation plate my set up is a 1994 Volvo Penta 7.4 with 290 DP

An over 17 year old thread. :doh: