I'm running wet exhaust and if you take these mufflers apart it would be really easy to change spring pressure. Once they are open they "lock" in place and back pressure is not needed to hold them open and once off plane the vibration from the motor will close them again. I never ran my boat without them but a 42 GTX (1000hp blower motors) ran a before and after and didn't see any effects on performance.

Anyone know why the can't be run dry?

Fred-
What did CMI say about installing these inside 5"OD wet exhaust pipes?
Thanks
Due

Theoretically, one could keep them in a partially to a full open position via spacers (or other methods) to adjust the sound level at lower speeds?

How loud would they be in the full open mode at idle?

These could be fun

Jamal

Yes.....there's a rubber seal inside that will burn up without the introduction of water. CMI is currently testing a couple variations with other materials that would take the heat of dry exhaust. I look for a dry version in the not to distant future.

Yes John...this can be done. The tails would need to be sent to CMI for the fitment and welding.

Do you have some downward pitch between the tops of the elbows and tailpipe exit?

Here's a better photo of the new design.....

Fred-
We'll put a level on the tailpipes to check the down pitch. Will CMI do work on Stellings tailpipes? They once told me they work only on CMI products.
Thanks!
J

I'll check.....

So I have 4 of these but changing from SC engines to NA. I was told by one person I should use different mufflers on my NA motors. I really dont want to spend $2000 on new mufflers if these would be safe/fine for my new application.