exhaust riser and manifold for mark 2 1997

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captran

A mechanic came aboard to look at one thing, but also poked around a bit (I'm sure that will cost extra), Said something was loose, and when checking near the top of the riser, there's a hose with a clamp and the clamp was broken.  Installed new clamp and no more wobble/looseness.
Randy Thies
Voyager  1997 #1345
was Florida, now Anacortes Wa

Jon W

#1
If it's leaking, it should be replaced. Depending on where the crack is, you could be leaking carbon monoxide into the cabin.

I have a 1987 MK 1. Each boat and vintage seems to be a little different, so the following is just a reference point for you.

I replaced the hose from the exhaust riser to the Aqualift muffler with a Trident silicone "hump" hose.

To do that I prepped the area to get access to everything. The steps were remove coolant, loosen the hose clamps, remove the riser, clean off the old gasket, remove the old hose, check Aqualift muffler for cracks, install the new "hump" hose, reinstall the riser with new gasket and sealant, add coolant, bleed coolant system. Time to do all of that was about 1 hour.

Does his 24-32 hour estimate include making a new riser? When you do this I highly recommend installing a "hump" hose instead of the standard exhaust hose. Really helps dampen engine vibration.
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, 35# Mantus, Std Rig
San Diego, Ca

KWKloeber

Quote from: captran on July 06, 2020, 09:08:56 PM

exhaust manifold adaptor ... leaking exhaust. 


Randy

I presume he's referring to the exhaust flange?  (removing and fixing the leak, presumably could be as "easy" as a new gasket.)
 
The unfortunate reality is that the vast majority of time/effort/lost skin on knuckles/cost is getting the old parts apart w/o ruining them (if that's even possible,) and if new studs are needed and/or if the flange can be reused or needs replacing -- so that simply fixing that leak and not replacing the whole shebang seems a waste.  e.g., How many years will it be before the riser needs to be replaced (if indeed it's only rusty and not about to fail.)  Make sure the new gasket goes on facing correctly -- on backward, you dump all your coolant out the exhaust (and need to start all over.)

-ken
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Ron Hill

#3
Randy : I believe that Ken is correct.  If it is the Gasket between the exhaust flange and the exhaust manifold all you need is a $5 gasket!!

Can't recall when Gerry Douglas said the hump hose was standard C34 MKII production - thought it was with the first MKII hull # 1295?

A few thoughts

Ron, Apache #788

Jon W

#4
Randy, if Ron's memory is correct your number boat should have a silicone "hump" hose installed. If it were me I would put in a new silicone "hump" hose. The boat is 23 years old, and if you're removing the exhaust riser for repairs, it's a perfect time to also change that hose and check the Aqualift muffler for cracks. Then you know that system is good for a long time.
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, 35# Mantus, Std Rig
San Diego, Ca

Stu Jackson

The hump hose connects from the end of the exhaust riser to the muffler.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Noah

#6
This is a hump hose:
Disregard the rust. Been cleaned up since photo. 8)
1990 hull #1014, San Diego, CA,  Fin Keel,
Standard Rig

Jon W

#7
To avoid any cornfusion, the blue hose is the "hump" hose.  8)
Jon W.
s/v Della Jean
Hull #493, 1987 MK 1, M25XP, 35# Mantus, Std Rig
San Diego, Ca

Ron Hill

Guys : The MKII C34 has a different muffler that that of a C34 MKI. 
That hump hose is fairly resilient and I'd call Tri Dent and ask them about the life span of their hump hose.

A few thoughts
Ron, Apache #788

KWKloeber

Quote from: captran on July 07, 2020, 07:17:58 AM

I just don't know enough to know what to look for.


Rsndy

if you mean for the leak itself, you can usually tell/locate an exhaust leak w/ her running.  If you puff some baby powder around there you might see a telltale exhaust leak blowing it.

If you mean generally, you need to unwrap it, and start poking the bear to determine if it's all competent pipe or corroded/thinning.  If you whack at it and it's competent it shouldn't dent (heavy pipe.) 

A screwdriver or heavy icepick will tell you if you can puncture the riser anywhere or if it's about "to go."  Or tap on it w/ a small ball pein hammer to locate weal spots (sound different) 

Elbows and the water injection wye are typical fail points.
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

KWKloeber

As Capt Ron said, different muffler.  Side in, (right angle) top out.
It still would not hurt (opinion) to use a silicone hose on the inlet side - more flex and less probe to transmitting vibration. Or a non-wire-wound exhaust hose or corrugated exhaust hose.
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Ron Hill

Randy : Absolutely get a silicone hump hose between that riser and the inlet to the aqua Lift muffler.
Like I said I thought that Gerry Douglas told me that the MKIIs had them installed.  Must be later production than yours?

A few thoughts
Ron, Apache #788