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Installing New ETX Manifolds


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So I need to replace the ETX manifolds on my RLXI. The closest Malibu dealer is 2 1/2 hours away. Not sure I trust any of the local boat shops to give me a reasonable price for installation only. So my question is how difficult is it to install the manifolds. From what I can tell there are 5-6 bolts that hold the manifold to the engine. Is it just a matter of taking out the bolts, removing the old manifolds and installing the new ones? Do the bolts need to be tightened to a specific torque? Any tips on how to make life easy for the installation. Or am I just better off taking it to the dealer?

Thanks for the help.

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Mino, is corrosion/oxidation a problem where you ski? What happened to the O/E manifolds? Before replacing with anything have a look at hitekmarine.com.au. They make a direct replacement Indmar fully jacketted header that looks the business and is a straight bolt on. Thay also claim significant improvements in fuel economy and performance.

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As was stated, unbolt the old ones and install the new ones. Couple of questions though. Are you getting new oxygen sensors with the new manifolds? If not you will have to transfer those over. The rear set of O2s you can use a regular wrench on, but the front set are recessed so you will need an "oxygen sensor socket" to remove them. The wires are just in the way.

If you don't get new gaskets with the new manifolds the originals should be reusable if they are stamped stainless steel. Just clean them up with brake cleaner and coat them with some red "high temp" silicone around the ports. This just helps to ensure a good seal, it's not a bad idea to do it on new gaskets either.

The bolts are relatively low torque, you should be able to tell when breaking them loose. 15-20 ftlb is the normal, make sure they are torked evenly. This just ensures that you don't crack one but not too much of a big deal. They are pretty thick castings and don't get too hot (compared to a car), so you should be ok.

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Mino, is corrosion/oxidation a problem where you ski? What happened to the O/E manifolds? Before replacing with anything have a look at hitekmarine.com.au. They make a direct replacement Indmar fully jacketted header that looks the business and is a straight bolt on. Thay also claim significant improvements in fuel economy and performance.

dihrdskir

Thanks for the info. The plugs in the old manifolds corroded and started to leak on the one side. After further inspection I saw the other side was starting to corrode as well. Boat has never been even close to brackish or salt water. Called Indmar and explained the problem and lets just say they were not very helpful. My old dealer and Malibu were much more helpful. Already have the replacements, just trying to decide if I want to do it myself or take the 2 1/2 hour ride to the Malibu dealer.

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As was stated, unbolt the old ones and install the new ones. Couple of questions though. Are you getting new oxygen sensors with the new manifolds? If not you will have to transfer those over. The rear set of O2s you can use a regular wrench on, but the front set are recessed so you will need an "oxygen sensor socket" to remove them. The wires are just in the way.

If you don't get new gaskets with the new manifolds the originals should be reusable if they are stamped stainless steel. Just clean them up with brake cleaner and coat them with some red "high temp" silicone around the ports. This just helps to ensure a good seal, it's not a bad idea to do it on new gaskets either.

The bolts are relatively low torque, you should be able to tell when breaking them loose. 15-20 ftlb is the normal, make sure they are torked evenly. This just ensures that you don't crack one but not too much of a big deal. They are pretty thick castings and don't get too hot (compared to a car), so you should be ok.

Wayne,

Thanks for the info. I did not get new oxygen senors. Is it a good idea to replace these at the same time as the manifolds? The boat has about 275 hours on it. Regarding the gaskets, I had heard that Malibu recommends using the high temp silicone instead of actual gaskets. Is this true? Should I get a torque wrench to make sure they are even?

Thanks again for the help.

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No need to replace working sensors, I would just transfer them over. Just make sure the threads are good after you remove them from the old manifolds and use some anti-sieze when installing them on the new manifolds. Also make sure the little sealing washers stay on the sensors.

You can get away with no gaskets at all and just use red high temp silicone. I would just reassemble it like it was when you take it apart, just use fresh sealant and clean all the surfaces really well.

My thoughts on the torque wrench.....you can get away with out using one if your mechanical experience is pretty good. In other words if you have a feel for it you can do with out. Intake manifolds are a little more sensitive to even bolt torques. The exhaust manifolds shouldn't need any more than a short 3/8 inch ratchet to tighten them sufficiently. Otherwise get a torque wrench, they are a good investment. You could get away with an adjustable "clicker" style from craftsman that will last you for a lifetime. If you plan on doing more work on your own, they are worth having.

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Mino, is corrosion/oxidation a problem where you ski? What happened to the O/E manifolds? Before replacing with anything have a look at hitekmarine.com.au. They make a direct replacement Indmar fully jacketted header that looks the business and is a straight bolt on. Thay also claim significant improvements in fuel economy and performance.

dihrdskir

Thanks for the info. The plugs in the old manifolds corroded and started to leak on the one side. After further inspection I saw the other side was starting to corrode as well. Boat has never been even close to brackish or salt water. Called Indmar and explained the problem and lets just say they were not very helpful. My old dealer and Malibu were much more helpful. Already have the replacements, just trying to decide if I want to do it myself or take the 2 1/2 hour ride to the Malibu dealer.

My plugs started leaking also. Called Indmar They said they sell replacement plugs that I could weld in. I said it must be a common problem if you sell replacements did you change the material on newer ones I asked? I don't think I got a clear response. wasn't impressed.

So I sanded them all and JB welded them. that was Spring there still good to go but when and if they start leaking again I'll take them off and weld some plugs in myself if it looks like it's worth it after inspection. other then that I would probably buy the cast iron ones.

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No need to replace working sensors, I would just transfer them over. Just make sure the threads are good after you remove them from the old manifolds and use some anti-sieze when installing them on the new manifolds. Also make sure the little sealing washers stay on the sensors.

You can get away with no gaskets at all and just use red high temp silicone. I would just reassemble it like it was when you take it apart, just use fresh sealant and clean all the surfaces really well.

My thoughts on the torque wrench.....you can get away with out using one if your mechanical experience is pretty good. In other words if you have a feel for it you can do with out. Intake manifolds are a little more sensitive to even bolt torques. The exhaust manifolds shouldn't need any more than a short 3/8 inch ratchet to tighten them sufficiently. Otherwise get a torque wrench, they are a good investment. You could get away with an adjustable "clicker" style from craftsman that will last you for a lifetime. If you plan on doing more work on your own, they are worth having.

Wayne,

Looking at the manifolds I don't see where the oxygen sensors would be. Would they be on a 2005 RLXI with a monsoon? My boat does not have the CAT system.

Let me know. Thanks

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Stainless Marine makes exhaust manifolds (high performance)and are located near you. You probably need to make sure you have good zinc plugs in the manifold to slow the corrosion process. The zinc takes the corrosion and can be easily changed when used up.

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mino,

i bought a set of used etx's with 40 hours on them for 700.00

they went on my 1999 sunsetter lxi, its a 350 indmar 310 hp carb motor.

i replaced the cast iron manifolds to save weight and get a little more free flow.

red hi temp silicone and 30lbs of torque for the 3/8's bolts. no need to take it to the dealer, about 45 minutes and you can have both done.

i know that they are expensive if you need to replace them, as a matter of fact i could not even buy them from indmar or malibu. they told me my boat didn't come with them so i couldn't buy them.

anyway back to what you asked its a very easy change, hope this helps steve

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mino,

i bought a set of used etx's with 40 hours on them for 700.00

they went on my 1999 sunsetter lxi, its a 350 indmar 310 hp carb motor.

i replaced the cast iron manifolds to save weight and get a little more free flow.

red hi temp silicone and 30lbs of torque for the 3/8's bolts. no need to take it to the dealer, about 45 minutes and you can have both done.

i know that they are expensive if you need to replace them, as a matter of fact i could not even buy them from indmar or malibu. they told me my boat didn't come with them so i couldn't buy them.

anyway back to what you asked its a very easy change, hope this helps steve

Steve,

Thanks for the info. It does help. Could more questions. You mention the red hi temp silicone. What is the difference between that and the black high temp stuff like this?

http://www.bakesonline.com/detail.aspx?ID=1559

Also, did you use a torque wrench for the bolts? Finally, for the T-fitting and the drain plug that are on the bottom of the manifold, did you use anything on the treads like pipe dope?

Let me know. Thanks again for the help.

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mino,

i used a low volatile smell red hi-temp silicone on everything that is a higher temp application, seems to work the best for me.

as for the torque wrench, i do enough work on motors that it is just a feel for me to snug them up to about 30 ft lbs.

if you don't feel comfortable your can rent a torque wrench at your local auto parts store. its really not that critical to have the manifolds torqued exactly to 30 but just to get a good feel that everyone of the bolts feels close. the fittings i used just teflon tape.

if ya need more info send me a pm with your phone number and a good time to call, i'm est time zone. steve

Edited by sgt1970-442
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