Winterizing EMI Thunder Risers

[Slide]

This year I bought a Sea Ray Pachanga with a built 502. It has aftermarket EMI Thunder risers. While winterizing I drained them from the input hose but noticed that there is a plug at the base of each riser. EMI's site says these are so you can put the input wherever you want - do I need to pull all of these plugs to fully drain them?

To clarify - the input hose is the lowest point on the whole riser, just checking for anyone else who runs these to verify if the other plugs need to be pulled.

 

[Fun Times]

Re: Winterizing EMI Thunder Risers

Hi there, Some early EMI models had small brass drain plugs at the bottom of the manifold. One on each cylinder and if I recall correctly, they were allen head type plugs.

But they may have changed designs over the years. I'm pretty sure you don't have to pull the three top inlet plugs but for reassurance, you should call Eddie marine in Rancho Cucamonga, CA due to you don't want to be wrong because the cost of new EMI's can be pretty high.

Eddie Marine : Contact Info

Let us know what you find out, Good luck.

 

[alldodge]

Re: Winterizing EMI Thunder Risers

I have the newer stainless steal design and the there is very little water left in the riser after shutting the engine off due to slope. If freezing does happen there is plenty of room for it to expand up and to the rear. Just sent an email to EMI to ask them just incase I'm missing something myself

 

[Bondo]

Re: Winterizing EMI Thunder Risers

Ayuh,.... A picture would help, but there should be No reason to pull any alternative plumbin' plugs to drain 'em,....

 

[Slide]

Re: Winterizing EMI Thunder Risers

Thanks for the replies - I got some feedback from another local boater who has had multiple sets of EMIs, and draining from the main input is all that is required. I figured as much since I drained them after the block and not much water came out, but I wanted to be sure.

Fun Times, it does have the allen plugs at the base of each cylinder riser, those are the ones that I noticed. I believe all EMIs have these. I'll probably crack one open to be sure but I believe my problem is solved.

 

[Fun Times]

Re: Winterizing EMI Thunder Risers

Thanks Slide!

Have a question/favor to ask of you and/or alldodge.

If possible, would either of you be willing to do a small detailed write up with photos of how to go about draining EMI's?

Reason I ask is, there really is no information online about how to do it properly that I could find. It may just help future Google searchers.

Thanks guys for the consideration.

 

[alldodge]

Re: Winterizing EMI Thunder Risers

Called Eddie Marine and didn't get clear answers to some of my questions. The guy was being a devils advocate and mentioned things like; to be sure you could add some antifreeze. The only one he was clear about was the older style risers which have holes that go from the manifold to the riser. The old style only needs to have the manifold drained, in doing so will also empty the riser.



That being said I pulled the riser hose off mine and from the picture you can see the passage way is about 1/8 inch gap to the side. The bottom gap is a bit less. When I pulled the fitting off only a couple drops of water was noticed. With very little water being available for freezing, the riser being made from stainless steel, the thickness of the riser is more then adequate, I would not worry about freezing being a problem.



In conclusion and in my opinion, draining the exhaust manifold for either old or new style, BB or SB EMI exhaust systems is good enough to protect them for winterization.

 

[Slide]

Re: Winterizing EMI Thunder Risers

AllDodge - I'm not surprised EMI was not totally straightforward. Better to recommend to fill it with antifreeze then accidentally recommend a wrong method to winterize a setup you can't physically see!

That said, my setup is identical to your first image, we may have the exact same risers. I had to refill the system today so I could warm up the oil for draining. Afterwards, I pulled off the input hose at the elbow (did not remove the fitting). I got a lot more water out versus pulling the block drain first, but I suspect a lot of the water in the risers drains down to the block if that is the only point open.

Fun Times - I can add photos later if you like, but in my estimation:

TO DRAIN EMI RISERS:

Disconnect the input hose. This will drain most of the water in the risers - any leftover pockets will have plenty of internal space to expand. If your setup has an alternative input location that is not the lowest point on the riser, open the Allen screws at the base of each cylinder riser to ensure full drainage.

 

[Bondo]

Re: Winterizing EMI Thunder Risers

AllDodge - I'm not surprised EMI was not totally straightforward. Better to recommend to fill it with antifreeze then accidentally recommend a wrong method to winterize a setup you can't physically see!

That said, my setup is identical to your first image, we may have the exact same risers. I had to refill the system today so I could warm up the oil for draining. Afterwards, I pulled off the input hose at the elbow (did not remove the fitting). I got a lot more water out versus pulling the block drain first, but I suspect a lot of the water in the risers drains down to the block if that is the only point open.

Fun Times - I can add photos later if you like, but in my estimation:

TO DRAIN EMI RISERS:

Disconnect the input hose. This will drain most of the water in the risers - any leftover pockets will have plenty of internal space to expand. If your setup has an alternative input location that is not the lowest point on the riser, open the Allen screws at the base of each cylinder riser to ensure full drainage.

Ayuh,... The risers drain through the Manifold drains,... There's No connection to the Block drains,....

 

[alldodge]

Re: Winterizing EMI Thunder Risers

AllDodge - I'm not surprised EMI was not totally straightforward. Better to recommend to fill it with antifreeze then accidentally recommend a wrong method to winterize a setup you can't physically see!

That said, my setup is identical to your first image, we may have the exact same risers. I had to refill the system today so I could warm up the oil for draining. Afterwards, I pulled off the input hose at the elbow (did not remove the fitting). I got a lot more water out versus pulling the block drain first, but I suspect a lot of the water in the risers drains down to the block if that is the only point open.

Fun Times - I can add photos later if you like, but in my estimation:

TO DRAIN EMI RISERS:

Disconnect the input hose. This will drain most of the water in the risers - any leftover pockets will have plenty of internal space to expand. If your setup has an alternative input location that is not the lowest point on the riser, open the Allen screws at the base of each cylinder riser to ensure full drainage.

My risers do not have allen screws. Did you pull the lower hose off before you removed the upper one? If not this could be why you go more water out. There is next to no gap at the bottom inside of the riser, it's sort of an inverted cone going up. The largest gap is at the very top of the input hose on the riser. I see it as having plenty of room to expand upward. Either way I pulled the port off for pic's and inspect, I'm leaving the starboard side untouched.