99 Response 3 1/2” exhaust hose length

[aupatking]

I picked up this 99 about a week ago with totally trashed exhaust hoses from manifold to fiberglass silencer tubes. I just got a new  hose to cut and it “appears” the old ones were about 27” long. Can anyone verify the correct length? It appears the easiest way to replace them is to remove the rear seat (any help there as well?) and place it all back in the lower hull. I’d much rather cut long, and remove length as needed, but it would be so much nicer to have the correct length to start. The new hoses do not like bending. 

[aupatking]

Non-cat, of course. Also, any tips on getting the correct bend would be a great help

[Bozboat]

Which mufflers are you using or are you going straight exhaust?

Exhaust flappers to the muffler should be smooth hose, from the muffler to the exhaust manifold should be the wire reinforced bendable hose.

Edited March 31, 2023 by Bozboat

[justgary]

My Sunsetter had rigid hose from the factory, so that's what I used to replace it.  It is a chore to get it tucked in front of the engine hood cross bar, but it can be done.  I'm sure you will want to replace the aft sections of hose as well.  No sense running around with rotten hoses.

I would probably do the following:

1. Remove the aft section of hose so you can easily move the silencers around.
2. Carefully place the silencers so that the angled tips point straight toward the exhaust riser outlets, and maybe bias them a bit forward to allow the hood crossbar room to fit.
3. Now measure from the angle of the silencers to the upper end of the riser outlets.  Cut the hose maybe 1/2" longer than this measurement.
4. Temporarily assemble the hose sections on the silencers, then the risers.  Install the hood crossbar.  You may need to trim the hoses a bit to make everything fit.
5. Now measure the aft section from the silencer to the flapper tips.  Cut the hose the full length from the flapper flanges to the forward end of the silencer sleeve.
6. Remove the crossbar, silencers, hoses, and the exhaust risers.
7. Inspect the manifolds and risers to make sure you still have enough water jacket to keep from letting water into the cylinders.
8. File the manifold and riser mating surfaces to make sure everything mates flush.
9. Install the rear hose sections on the flappers, then on the silencers.
10. Install the forward hose sections on the silencers, then the risers onto the hoses.  Make sure the hoses are seated fully.
11. Install the crossbar to help hold things in place.
12. Use new riser gaskets and mate the risers to the manifolds.  Trim the upper hoses only if you absolutely can't get the risers to mate.  Using a few extra long bolts can help get the risers lined up so you can push them down and start the shorter bolts.
13. Make sure you use two hose clamps per hose connection, and double-check that they are all tight.

I can't think of a better way to sink a boat than to have an exhaust hose failure, so take your time, clean all mating surfaces, and use quality materials.

[aupatking]

Where are the bolts/screws that hold the back seat?

[UWSkier]

2 hours ago, aupatking said:

Where are the bolts/screws that hold the back seat?

There are two angle brackets at the bottom of the couch that screw into the floor.  There are some lag bolts that screw in from under the gunnels into the side of the sofa on each side.  Three on each side on my boat  Remove your speakers for easiest access.  There are also some screws that hold the base of the side panel into the base of the couch.  See arrows.

 

Edited March 31, 2023 by UWSkier

[Woodski]

Are we to assume you can't properly measure what is there due to it is too torn up to measure?  Mine are more in the 27.5" length although I have a custom made system and more importantly the riser will dictate the length (and different marinisers use different ones).  You can always remove the existing pipes and measure that way.  I would put a small spacer under the leading edge of the muffler to measure so when system is complete it does not touch the floor.   Another approach to install the stiff rubber pipes:  have the clamps on the tail pipe end loose to allow the muffler to rotate.  Rotate the muffler so the riser side is pointing about 45+ degrees towards center.  Slide the exhaust hose on to the riser end and then you can 'muscle' the muffler end over the muffler inlet and rotate the muffler to vertical and the hose will (with some persuasion) go right over the inlet to the muffler.  Don't forget to have the clamps already on the hose just to make that part a little easier.  Some soapy water or even WD40 to allow the hose to slip on the riser will help.  

https://www.hardin-marine.com/p-46-3-12-marine-grade-soft-wall-exhaust-hose.aspx

[aupatking]

@Woodskithat’s about what I measured, but I cut my first one to 28” just to make sure. With the back seat in, you can’t get anywhere close to the angle you need on the fiberglass muffler, and with the hose just connected to the riser, the damn thing looks about 6” too long. I know it’s not that much too long, but it definitely made me question it. One of the hoses had been removed and left in the sun for a couple years and yeah, it was definitely too trashed to measure. I’m going to pull the seat tomorrow and will try to remember to get some pictures. I should have gotten before and after of the whole project but I had to get it clean enough the night I brought it home that my wife wouldn’t divorce me in the morning for bringing the thing home. 

[aupatking]

@UWSkier how many and are the screws from the sides (through the carpet) accessed from behind.  I just fished around in the carpet but I really can’t find them? What engineer thought that was a good idea

[Bozboat]

Just now, aupatking said:

@UWSkier how many and are the screws from the sides (through the carpet) accessed from behind.  I just fished around in the carpet but I really can’t find them? What engineer thought that was a good idea

It’s going to be random 

a magnet will help you locate them 

[UWSkier]

On 4/1/2023 at 5:23 PM, aupatking said:

@UWSkier how many and are the screws from the sides (through the carpet) accessed from behind.  I just fished around in the carpet but I really can’t find them? What engineer thought that was a good idea

2 on each side on my 01. Through the carpet. Feel around with a screwdriver. 

[Woodski]

@aupatking - think positively, this endeavor will provide you with the knowledge of how much and how painfully you can twist, bend and contort your body and the ability to learn a variety of new swear works by the time you get the seat back unfastened.   

[hmh800]

I removed the iron elbows from the tops of my exhaust manifolds when I replaced the exhaust hoses on my sun setter.  I couldn’t see getting enough bend in them to get them over the elbows with them in place.  I then replaced hoses from transom forward.  It wasn’t bad.

[aupatking]

Thanks all. I got the seat out, I’m going to replace those screws with countersink washers and screws on the OUTSIDE of the carpet. I’m also going to test a theory on getting the bend I need. If it works, I’ll post pictures. If not, we’ll forget this sentence ever happened. 

Ive got access to an EControls ecm and wiring harness. I really think I can ZO this boat for within about $500 of what it would run to update the PP. If that’s the direction I go, I’ll make another thread for it.

[Bozboat]

This would be a good time to replace the fuel lines while you have it all opened up.

[justgary]

9 hours ago, Bozboat said:

This would be a good time to replace the fuel lines while you have it all opened up.

This.

And add a transom flush port if you are an engine flush kind of a guy.  I used a Mar-Pac 7-0418 fitting mounted a few inches from the starboard lift eye on the transom.

[Woodski]

And since you are a BOS member (ie: slalom addict), just park that back seat in the attic.  The Response responds very well to removing weight from the transom.   Low fuel and anything you can move out of that area will flatten / soften the wake.  For appearance, you can make a lightweight panel that covers over where the seatback resides and cover it with carpet or vinyl.  Opening up that area makes it much nicer to step to / from the platform to the boat.

[Michigan boarder]

Also, wetted exhausts are not very hot, don't think of them like a normal car exhaust.  I can rest my hand on the exhaust manifold when it's running.  So, that opens up options for bends.  Here I've got PVC fittings to make the 45 degree elbow at the bottom, and coming right off of my manifolds I have silicone turbo tubing that I trimmed to make work.  I've been running this set up since 2016 and a couple hundred hours from idling for hours around the lake to footing for hours with a group.  The silicone fittings make is super easy to assemble.

 

 

[UWSkier]

15 hours ago, aupatking said:

Thanks all. I got the seat out, I’m going to replace those screws with countersink washers and screws on the OUTSIDE of the carpet. I’m also going to test a theory on getting the bend I need. If it works, I’ll post pictures. If not, we’ll forget this sentence ever happened. 

Ive got access to an EControls ecm and wiring harness. I really think I can ZO this boat for within about $500 of what it would run to update the PP. If that’s the direction I go, I’ll make another thread for it.

You can't ZO that boat unless you can source all the parts to convert to throttle-by-wire.  If you do it, DEFINITELY post another thread since this is something I'd love to do to my '01.

Since you have the back seat out, you may as well pull off one of the sides and remove the fuel tank too. 

And since you're doing all of that, you may as well drop the rudder out and change the strut bushing.

Early in the COVID era, I took on a project to replace my strut bushing and ended up with all new fuel and exhaust lines, new flooring, leveled flooring, repaired gunnel netting, cleaned injectors, nearly dripless packing...  snowball

Edited April 4, 2023 by UWSkier

[aupatking]

@UWSkieryou went all the way down that rabbit hole . I tried a ratchet strap from the engine mount. It showed some promise but I think theres just no way to avoid removing the elbows. I’ve got 5/16s hex head bolts that, with those indents for the back 2, I can’t get my big Allen’s/hex heads on. Gotta raid my fathers tool shop to see what he’s got that may fit in those small insets. Any good tips there? This is going slower than I’d like, just due to available time. Should be on the water this weekend though. 

As for the ZO, I just have to find the right DBW throttle body. I’m pretty sure I found a potentiometer setup that will work. May have to get Jody to flash the ECM though. 

[aupatking]

Oh yeah, while I’m in there, what’s the thru-hull box called again? And, what’s the best way to make sure it doesn’t leak? I know there’s a thread on that here somewhere but can’t remember the name of the box. HCS box?

[Steve B.]

HDS. Hydrophonic Dampening System? 

[justgary]

Those socket head cap screws on the risers are a real pain.  A ball end allen wrench should get them.  I replaced mine with standard hex head bolts when I put them back on.

A few years later I replaced the whole manifolds with Marine Torq Stainless.

[UWSkier]

13 hours ago, aupatking said:

@UWSkieryou went all the way down that rabbit hole . I tried a ratchet strap from the engine mount. It showed some promise but I think theres just no way to avoid removing the elbows. I’ve got 5/16s hex head bolts that, with those indents for the back 2, I can’t get my big Allen’s/hex heads on. Gotta raid my fathers tool shop to see what he’s got that may fit in those small insets. Any good tips there? This is going slower than I’d like, just due to available time. Should be on the water this weekend though. 

As for the ZO, I just have to find the right DBW throttle body. I’m pretty sure I found a potentiometer setup that will work. May have to get Jody to flash the ECM though. 

I took an angle grinder to one of my allen wrenches to make one fit into those recesses.  It was a pain in the a**.  Oh yeah.  I also replaced riser gaskets when I did this project.  LOL forgot about those.