September 28, 2018 at 10:31 pm #17321
First time here so I’m hoping that someone can answer my question. I have a 1977 searay sda 240 with twin 470’s and I am going to put in exhaust shutters. What I have run into is the shutters are gone but the bars are still in place. The brackets that are holding the bar looks like a spring loaded type that are rivited to the top of the exhaust pipe one on each side and are about 4 to 6 inches long, question I have is how do you get the bar out of the bracket so I can insert new shutters? The shutter # is 45556 that is suppose to fit.
September 28, 2018 at 11:19 pm #17324
- This topic was modified 8 months, 3 weeks ago by loyddinneen711.
Basically the manual says to chisel away the two rivets on one of the shutter supports. There is more to it as far as sealing the ends of the shutter shaft and the bending of some tangs, My manual is in the form of a PDF and I can’t break out parts of it because of the software I use.
I will try to get the info to you.September 28, 2018 at 11:30 pm #17325
Thanks for your reply I will appreciate any help you can give me. Taking off one side does make alot of sense.September 29, 2018 at 5:57 am #17326
Keep in mind the shutter opens down into the lower exhaust pipe. The manual says to replace the rivets with 10/32 round head screws (stainless) also ” be sure the head of the screw is to the outside of the exhaust elbow”–whatever that means—-. Apply silicone to the ends of the shutter shaft that goes in the part you removed when you cut the rivets –make sure the shutters open downward and put silicone on the end of the shutter shaft that goes in the shutter support that was not removed.
I would also give a look into the exhaust pipe to see if the broken shutter is in there, also look in to the exhaust holes on either side of the drive. The broken parts usually will pass out with the exhaust gasses and through the drive check behind the prop where the exhaust exits. My exhaust shutter (later model) is similar but there are only are three parts
September 29, 2018 at 8:51 pm #17328
- This reply was modified 8 months, 3 weeks ago by stractor.
Thanks for responding so quickly this imfo is VERY HELPFUL and answers my question completely. I will double check everywhere for shutter bits and pieces, I believe that the shutters have been missing for awhile. When I had the outdrives off I didn’t see any parts in the exhaust bellows or inside but I wasn’t looking for anything then. I have a endoscope coming so I can inspect inside the pipe and outdrive so I don’t miss anything. The previous owners have had the outdrives off before as the bellows were somewhat new so they may have already cleaned the area out and didn’t go further to replace the shutters or even know what they where. If you happen to have any pictures that would also be helpful, Thanks so much. LoydSeptember 30, 2018 at 5:15 am #17329
I have no pictures of your type of shutter. There is a picture in Merc manual #3 but it is missing from the later definitive 470 manual #8.September 30, 2018 at 7:28 am #17330
I don’t have any merc manuals but I have a retired merc mechanic friend that may have one I will check with him on Monday. Thanks LoydOctober 1, 2018 at 10:32 pm #17332
I just got my shutters in the mail and before I install them was wondering what direction the manual shows that they go in, the smooth side facing out with knobbed side in or the other way. I am still waiting for the ociloscope so I can look down inside the exhaust and check for loose bits, and I am about to go out to the boat and grind off the rivits from the brackets. All help is appreciated thanks. Loyd
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