Manis/Risers/Elbows

[Partyoffive]

Hi All

Im looking at purchasing an 09 350 dancer, 8.1s v drives. The manis are original, 350 hours on motors. I know the exhaust will need replacing given they are original. I have a few questions: While researching parts I see Mani kits with all gaskets etc, and separately elbows which are stainless. The mani kit is about 650.00-700, and the stainless elbow about the same. Is the riser part of the stainless elbow? I dont see a separate riser? Also, do the stainless elbows need to be replaced? Im looking at OEM/mercruiser parts, anyone have an idea of total cost if done by a mechanic? heard prices from 5-10k...big spread!

TY!

 

[CaptRonn]

Depending on your engine model you should have stainless risers, and all they need are clean and examination for cracks, and reinstalled.

My 8.1's don't have elbows as the riser is a curved tube (stainless)

$650-700 for the exhaust manifolds is about right. They are not difficult to remove and replace.

Have your manifolds been run in fresh water or salt water?

 

[Partyoffive]

Thanks capt Ron
I believe i have the same setup as you, hence my confusion...I see a curved stainless tube connected directly to the manifold. Assuming no cracks in the curved stainless riser, they dont need replacement as often as the mani?

The boat was in salt water, was not commissioned last year and spent the year on drydock

 

[CaptRonn]

The SS risers should be fine, just examine for cracks.

Hint: When you remove the old manifolds, put them on CL and sell them. That way you can recoup a few dollars.

 

[Partyoffive]

Thx again!

 

[Havana Shamrock]

Deleted I re read the post

 

[Partyoffive]

Hi sham
What post are u referring to that was deleted? In looking at your pics, those appear to be cast risers? Mine look like the “elbow” in the photo below.

 

[jmauld]

The SS risers should be fine, just examine for cracks.

Hint: When you remove the old manifolds, put them on CL and sell them. That way you can recoup a few dollars.

I’m going to piggy back on this post, if that’s okay. I’m picking up a 2010 390 with 8.1s. The stainless risers measured about 20F higher on the port side of each motor. The manifolds measured fine. Do you think it will be fine to replace the manifolds and clean/inspect the risers? The current owner doesn’t have records of the last replacement and the boat was used in salt water. Although it was dry stacked and has a salt away system installed.

 

[CaptRonn]

I’m going to piggy back on this post, if that’s okay. I’m picking up a 2010 390 with 8.1s. The stainless risers measured about 20F higher on the port side of each motor. The manifolds measured fine. Do you think it will be fine to replace the manifolds and clean/inspect the risers? The current owner doesn’t have records of the last replacement and the boat was used in salt water. Although it was dry stacked and has a salt away system installed.

Inspect the risers for defects, cracks and any other problem. If nothing noted, clean up and reinstall.

 

[jmauld]

What about the manifolds? Would you preemptively replace those?

 

[CaptRonn]

What about the manifolds? Would you preemptively replace those?

Probably not a bad idea.

See the attached file from Mercruiser. They have a procedure to check manifolds. But again, it boils down to your comfort level.

 

[jmauld]

Looks like a simple replacement. Visual inspection also looks simple enough. Thank you for the file.

 

[Havana Shamrock]

Hi sham
What post are u referring to that was deleted? In looking at your pics, those appear to be cast risers? Mine look like the “elbow” in the photo below.

I was responding to the post with pics of my rotten parts I deleted my text but the pics stayed for some reason.

 

[Tacoma290]

For more information on the 8.1 Manifolds and Risers, see the Official 2003.5-2008 340 Sundancer thread, posts 2727 for photos and 2738 for checking conditions and benchmarking.

 

[CaptRonn]

For more information on the 8.1 Manifolds and Risers, see the Official 2003.5-2008 340 Sundancer thread, posts 2727 for photos and 2738 for checking conditions and benchmarking.

Link to the post or thread?

 

[jmauld]

Link to topic page:
http://www.clubsearay.com/index.php?threads/official-2003-5-2008-340-sundancer-thread.59501/page-137

2727: http://www.clubsearay.com/index.php...-sundancer-thread.59501/page-137#post-1182724

2738: http://www.clubsearay.com/index.php...-sundancer-thread.59501/page-137#post-1186474

 

[Tacoma290]

@jmauld, thanks for the assist!

 

[jmauld]

No problem. You mentioned the temps on the manifolds. Do you have any thoughts on a 20 degree difference in temp on the stainless risers? Both engines had this condition where one side was higher than the other. I don’t have the boat yet so I haven’t been able to pull and inspect. My plan is to run it for a month or so and then pull to inspect.

 

[CaptRonn]

No problem. You mentioned the temps on the manifolds. Do you have any thoughts on a 20 degree difference in temp on the stainless risers? Both engines had this condition where one side was higher than the other. I don’t have the boat yet so I haven’t been able to pull and inspect. My plan is to run it for a month or so and then pull to inspect.

That's not unusual. Mine have a difference between sides as well.

 

[Tacoma290]

No problem. You mentioned the temps on the manifolds. Do you have any thoughts on a 20 degree difference in temp on the stainless risers? Both engines had this condition where one side was higher than the other. I don’t have the boat yet so I haven’t been able to pull and inspect. My plan is to run it for a month or so and then pull to inspect.

I agree with Captain Ron. Twenty degrees is not that far off. If you do infrared readings, the numbers jump if you move to a different spot on each riser.