3.0 mercruiser exhaust Help

[Pikey23]

I have an 1984 fourwinns with a mercruiser 3.0L. When we bought it and ran it in the driveway (with muffs of course) I noticed that when it was in gear water and exhaust came out of the center of the prop, in neutral it came out from each side of the gimbal housing. . The other day while running it in the driveway I noticed that when in neutral exhaust came out of the gimbal. But, when I put it in gear it still only came out of the gimbal, not out of the center of the prop. What could be causing the exhaust to stop coming out from the center of the prop? Could the flapper have been broken off and stuck somewhere? Thanks for your help.

 

[tschmidty]

Re: 3.0 mercruiser exhaust Help

It could have but I wouldn't really worry about it, it is supposed to come out of the gimbal at idle and such. It will generally only come out of the prop under load.

 

[Pikey23]

Re: 3.0 mercruiser exhaust Help

OK. Thank You for your help.

 

[Bondo]

Re: 3.0 mercruiser exhaust Help

What could be causing the exhaust to stop coming out from the center of the prop? Could the flapper have been broken off and stuck somewhere?

Ayuh,... If it's Ever been run without water, that's quite likely...
They tend to get hung up in the bottom of the downpipe, or on top of the waterpump/ lower unit...

 

[Pikey23]

Re: 3.0 mercruiser exhaust Help

I had the lower unit out about 3 weeks ago and and did not notice anything. I replaced the impeller, housing and put new seals on the down pipe. I pulled the housing down that the pipe goes into just to check up there. I did not see anything. I guess I can pull it apart again and investigate further.

 

[tschmidty]

Re: 3.0 mercruiser exhaust Help

My flapper blew off as well and I did not find it in the outdrive. What I did to make myself feel better was to blow a shop vac both ways down the exhaust pipe disconnected at the flapper. Did not get anything out and did not hear or feel any obstruction so that eased my mind.