Changing Exhaust

[GetOnIt]

I have a 350, which is going to be replaced in my 1989 Larson. I want to put the Corsa Thru-transom exhaust tips on when I put it back together. I am also going to replace the manifolds. How do you install a thru-hull exhaust on a thru prop setup? Do I just run 4" hose from the manifolds down to the tips, where do I install the tips? I want to cap off the y-pipe. I will be using he muffler tips. By the way, to anyone that has these tips, how do they sound? Thanks for the help.

 

[Northern Eclipse]

Re: Changing Exhaust

I have the gil/corsa poewr tips installed in my boat, they sound great, you can remove the y-pipe and install a block of plate since you have to pull the old motor this would be best. You can connect the tips to risers with a approved rubber exhaust hoses which must be double clamped at each end. As far as location for the tips I can't comment on since I can't see your boat, you'll have to measure carefully and be sure nothing is in the way such has steering tiller. One thing to note that the rubber hoses can't be bent to far as to kink them,when ready to cut holes for tips be sure to use a good holesaw of the correct size 3" or 4" depends on the size of your exhaust now, and drill a small pilot hole first in the centre of each cutout, so holesaw bit has a good guide. Once holes are cut then seal any exposed wood core in transom with resin and seal tips with 3M 4200.

 

[GetOnIt]

Re: Changing Exhaust

Do the tips have to be lower than the manifolds so water can't run back into the engine? are they to be installed above the water line. The steering seems to be right where I would think to put them. If I go up it will have to go above the platform and it will be above the risers. If I go down it will probably be below the water line. Help, help, help...Thanks Guys

 

[Bondo]

Re: Changing Exhaust

Do the tips have to be lower than the manifolds so water can't run back into the engine?

Ayuh,........ Absolutely............<br /><br />It sounds like you'll Either have to go Below the swim deck,.........<br />Remove the swim deck,.......<br />Or,..<br />Stick with what you Have........

 

[jaybirdtx]

Re: Changing Exhaust

They need to go below the platform. Because the exhaust water and such will leave one helluva mess on the platform after a while. And they HAVE to be below the risers a bit. Be sure the tips have flapper valves installed to prevent water from entering the exhaust. Standing still I'm sure they are under the water line, but how about when the boat is under way? Do they come out of the water?

 

[f_inscreenname]

Re: Changing Exhaust

You can install them below the water line but when sitting still it will sound weird. Most I have seen either sit just above or at the water line.<br /> Here's mine.<br />

 

[LANCLJ]

Re: Changing Exhaust

The tips must sit above the water line, slightly above the top of your outdrive. Internally, your steering controls are going to dictate where the tips will exit.<br /> RAISE, don't eliminate, your swim platform to be just above the tips. Not hard to do.<br /> Make sure tips have internal and/or external flaps.<br /> You DON'T have to remove the y-pipe. You can get a pipe plug from any plumbing supply to cap off the y-pipe, in case you ever want to go back to thru-prop, or add diverters.

 

[GetOnIt]

Re: Changing Exhaust

Thanks for the help guys...The swim platform can't be moved b/c it is intigrated into the boat. I may just be stuck with what I have.

 

[LANCLJ]

Re: Changing Exhaust

Your not out of luck. When boat companies went to the so-called Euro-style hulls (integrated swim platforms), a lot of the performance boats came with side discharge exhaust tips.<br /> All of the performance parts guys: Eddie Marine, Livorsi, Stainless Marine, all make or sell side exit tips. These will exit on the side of the hull, just in front of the transom, above the waterline.<br /> Look into it before giving up on the idea.

 

[Scaaty]

Re: Changing Exhaust

How about punching some deck holes and run over the transom, like the old Jet boats?