2.4 exhaust question

[Blue197320]

hi all.
this is my first post on this board. i have just gotten my new engine. itsa a 84 2.4 200 merc ( original build with probably 10 hours ). the problem is it is bolted to a 97 200 2.5 midsection. i have the clamshell style cowl on this engine. it has the above water exhaust outlet that would normally be mounted in the 2.5 cowl. i need to find a way to plug it permanently or remove it so it wont interfere with my engine or anything. http://i62.photobucket.com/albums/h100/Blue197320/IMG_0102.jpg
if i am able to plug that hole do i need to open any other exhaust holes in the midsection so it will idle properly in the water?
thanks for any ideas or suggestions you may have.
-Evan

[Capt.Insane-o]

Automotive epandable freeze plug, the rubber ones with the nut in the middle. Then take a applicable size drill and drill out the relief slots just below the cowl and smooth them out with a die grinder or dremel. You can also use a brass plug to close the hole if you have a plumber friend with a tap that size.

[drasticplastic]

You need to "replace" the exh. hole you need to plug with the same or more amount of area. Like capt said you can do this in the non drilled out areas that would be open in a older 2.4 mid section. You can fill the old hole with an standard automotive freeze plug that fits in the hole snug and use J.B. weld to lock it in place.

[vnemous]

Why are these exhaust holes necessary if you exhaust relieve the bottom of the mid and remove the can? Thanks Mike

[vnemous]

Can't you just leave this hole open if you have a diff cowl that doesn't cover it? Thanks Mike

[Blue197320]

thanks for the replies guys. i will try the freeze plug and let u know how that goes. should i be concerened about the metal filings and shavings falling down into the mid section when i drill the holes ?

[drasticplastic]

No. The shavings will drop/wash out, the bottom of the gearcase(where the exhaust comes out) and the holes you make, when you start it up (on a hose). If you want you can blow some air in through the holes you are going to drill/grind to get the shavings headed down.

[drasticplastic]

vnemous, You need this exhaust relief for when the boat is sitting low in the water. Eg; at idle,not on plane and getting on plane. The cowl that he is going to run (old school "clam shell") would cover up/block the exhaust from comming cleanly out the hole in the newer mid-section.

[Capt.Insane-o]

If you use a tap in freeze lug be sure it's brass

[vnemous]

I am running a 2.4 200 with a 2.5 efi cowl. I just put on a 25" mid that has this hole that we are talking about. I can just leave it open yes? I plan two drill the holes in the cav plate also. Thanks Mike

[T-REX]

If U leave it open it won't hurt the runn'in, but it will have exhause exit'in in the lower part ov your cowl...Makes smoke cum out all over and makes a mess under the lower cowl.........Thoze 2 dummy holes(used to be open on earlier models) are just below the lower cowl...........Now, If your cowl rubber does not seel good, and exhaust git'z in your cowl(upper), your engine won't idle well at all!!!

[vnemous]

I have this cowl. THe exhaust hole will be below the skirt, I think. Thanks Mike

[vnemous]

T-Rex I just looked at a pic of my motor and I see what you mean. The hole will be behind my exhaust skirt. I guess I have to plug it and open up the other slots. Thanks Mike

[ProComp]

Just run it without the skirt or get a skirt from a ProMax. It has a hole in it to connect that rubber hose to.

[j_martin]

You can also use a brass plug to close the hole if you have a plumber friend with a tap that size.

Most tool rental places have large size pipe taps to rent.
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[Blue197320]

i did exactly what u guys told me i should do. i got the expandable freeze plug. had to shave it down a little and open the hole a little to make it fit. it is pressed right against the back of that opening i made. is that ok? the other side is now open as well. here are the after shots. http://i62.photobucket.com/albums/h100/Blue197320/IMG_0115.jpg
http://i62.photobucket.com/albums/h100/Blue197320/IMG_0116.jpg
http://i62.photobucket.com/albums/h100/Blue197320/IMG_0117.jpg
http://i62.photobucket.com/albums/h100/Blue197320/IMG_0118.jpg
everything should be workin fine now right?
-Evan

[T-REX]

U shouldn't have any problemz!!...lookz good.....

[Capt.Insane-o]

Beauty...

[Blue197320]

thank you so much for ur replies guys. i will start it in about a month and see how it does.
thanks again.
-Evan

[86vintage]

I have a 1995 200hp EFI. I have the exhaust tube working and I drilled the 2 rectanguler Old exhaust reliefs back open and the motor sounded great not to loud but a nice deeper exaust note. The motor responded well and had zero negative affects.
If I was in your situation I would vent the 2.5 exhaust tube out the back of the fiber glass Cowl not seal it, with a freeze plug?.
Leave it open - Let it breathe -
The more air(exhaust) you let out high like that - the better response you will have coming out of the hole.
if it don't work than plug it.
But I liked it!!http://forums.screamandfly.com/forums/images/icons/icon12.gif