Change Manifolds and Risers??

Ok here's a pic :)
 

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Be VERY careful with gasket replacement. From what my mech tells me, as Merc updates things, the gaskets get changed. OEM gaskets "A" and "B" may look the same but the holes are spaced differently. I cannot speak from personal experience. The fellow has been in business for 25 years.
 
My 97 last had the R&Ms done in 05 according to the maint records. I am going to be doing the job myself, buying Osco manifolds, made in USA. I started tonight by taking off the port side oil filter bracket and trying to get the riser off.
The problem I ran in to was the fact I couldn't lift the riser once the nuts were off because of the deck blocking upward motion. I have the spacer blocks with the long studs through them as well.
Question to you guys is whats the prefferred method of getting those studs out. I doused with liq wrench and tried vise grips on non threaded area, no dice yet. I saoked again and will try tomorrow, maybe torch?
 
Harmon said:
My 97 last had the R&Ms done in 05 according to the maint records. I am going to be doing the job myself, buying Osco manifolds, made in USA. I started tonight by taking off the port side oil filter bracket and trying to get the riser off.
The problem I ran in to was the fact I couldn't lift the riser once the nuts were off because of the deck blocking upward motion. I have the spacer blocks with the long studs through them as well.
Question to you guys is whats the prefferred method of getting those studs out. I doused with liq wrench and tried vise grips on non threaded area, no dice yet. I saoked again and will try tomorrow, maybe torch?
Click to expand...

I've found Kroil to be better than all other penetrants.

Is is it time to call an expert or maybe one will chime in here. I'd be afraid of snapping the thing off. Then what?
 
so do you have a problem with a physical blockage ( i.e., not enough room) or do you have a seized bolt? Perhaps it's both, but just was not clear. I would keep soaking, then use a breaker bar, but be mindful of bolt twisting, if you break it off it's torch time...
 
Here are pics of my risers, 10 years old in salt, 200 plus hours. I changed the manifolds as well; most likely could of gotten away with keeping originals, but just got paranoid. Job took 7 hours with a helper. It was pretty straight forward; toughest part was getting hoses off and managing coolant drainage.
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Harmon said:
My 97 last had the R&Ms done in 05 according to the maint records. I am going to be doing the job myself, buying Osco manifolds, made in USA. I started tonight by taking off the port side oil filter bracket and trying to get the riser off.
The problem I ran in to was the fact I couldn't lift the riser once the nuts were off because of the deck blocking upward motion. I have the spacer blocks with the long studs through them as well.
Question to you guys is whats the prefferred method of getting those studs out. I doused with liq wrench and tried vise grips on non threaded area, no dice yet. I saoked again and will try tomorrow, maybe torch?
Click to expand...

You may have to remove the manifold with the riser attached so you can lower the whole assembly and move away from the obstruction to lifting off the riser block.
 
No, not seized, the nuts came off easy as pie. The problem is with those long studs that go from the top of manifold , up through the spacer block and riser elbow. Its just a threaded rod so there's no nut to put a breaker bar on. I am griping the rod with vicegrips as hard as possible and trying to unscrew from the manifold, that way I can remove the riser,elbow and spacer block.
 
Put the nuts back on with an additional jam-nut, then you can get a wrench or socket with a bar on it to get more leverage. Also, if you are going to be replacing the manifolds anyway, is there any reason not to just cut the studs? Or are you planning to re-use them in the new install?
 
I looked up prices on http://mercexhaust.com/. I then told my local dealer (Merc authorized) if they could match MercExhaust's prices I'd rather buy them locally, from them and have them install them. They agreed and I was happy to have them do it.
[video=youtube;E3KN8IIh4Fw]http://www.youtube.com/watch?v=E3KN8IIh4Fw[/video]
 
I will try the jam nut again, I tried last night but I think I stripped half the threads off a nut. They are fine thread and maybe I didn't grab enough. Thanks.



src said:
Put the nuts back on with an additional jam-nut, then you can get a wrench or socket with a bar on it to get more leverage. Also, if you are going to be replacing the manifolds anyway, is there any reason not to just cut the studs? Or are you planning to re-use them in the new install?
Click to expand...
 
Harmon said:
My 97 last had the R&Ms done in 05 according to the maint records. I am going to be doing the job myself, buying Osco manifolds, made in USA. I started tonight by taking off the port side oil filter bracket and trying to get the riser off.
The problem I ran in to was the fact I couldn't lift the riser once the nuts were off because of the deck blocking upward motion. I have the spacer blocks with the long studs through them as well.
Question to you guys is whats the prefferred method of getting those studs out. I doused with liq wrench and tried vise grips on non threaded area, no dice yet. I saoked again and will try tomorrow, maybe torch?
Click to expand...

not the preferred way but I have heard of mechanics welding a nut onto the threaded rod to get the rod out.
 
gerryb said:
not the preferred way but I have heard of mechanics welding a nut onto the threaded rod to get the rod out.
Click to expand...

I imagine that's only when they are saving the manifolds. Since he's scrapping them, there's really no need to put too much effort into freeing the studs in a "clean" manner. Cut the suckers off and move on, I say.
 
I shimmed up the riser and cut bolts off with 4" angle grinder, sparks a flying!! I was using a shirt to block the spray but it caught on fire and had to snuff it out!! close one.
All three pieces are in great shape, I mean for 9 years old its crazy. No blockage, no scaling or flaking in the exhaust port and only minor rust in water jackets,from pictues posted here, these look like a few years old, OEM makes a difference.
I only put about 100 hrs on the boat since 2011.
I guess to be safe, I will replace, but I'm bringing them with me to show the guy at the store. Nuwave exhausts have great prices on OEM stuff.



src said:
I imagine that's only when they are saving the manifolds. Since he's scrapping them, there's really no need to put too much effort into freeing the studs in a "clean" manner. Cut the suckers off and move on, I say.
Click to expand...
 
Hi guys, as another question for this thread do you re-torque your bolts after new manifolds, risers and gaskets and you've been running for a few hours??

Thanks in advance
 
Last edited:
MarkIC said:
Hi guys, as another question for this thread do you re-torque your bolts after new manifolds, risers and gaskets and you've been running for a few hours??

Thanks in advance
Click to expand...

I just replaced all of mine and am going to check torque at around 5 hours. Going to St. Micheals for the antique boat show this weekend and will check them when I return. I think it is a good idea since the manifolds are cast and prone to cracking if unequally torqued.
 
I bought all new since 9 years is way out of spec, I am impressed with the lack of wear though.

Next issue: cleaning heads for new gaskets and I see third port on port side has almost an extra amount of metal right around the inside lip of the port. ITs as if the 1: the cast was bad from begining or rest of metal towards outside of the port is going away. I am using a razor scraper and it is def metal, weird. Coincidentally this port has the most build up inside (carbon/flakes)

ANy thing to worry about? Motor has 469 hrs for a 97 7.4ltr
 
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