Hi All,

thank you for your comments. I’ll be able to get to the boat over the next few weeks and will do further investigation and feedback. For sure the pipes are ‘straight through’ there is no captains call/muffler box/swim platform exit.

I will check the pipes for any internal muffler, and also intend to check condition of the manifold and risers at same time.

Off on a bit of a tangent but does anyone know how CMI and the other stainless manifold companies do the mandrel bending of the nested tubes? I assume they bend the internal and external tube separately, but it seems that it would be difficult to get the tubes to nest given some of the complex bends close to the head. I wonder whether there is some way they are bending them nested?

I might have a go at fabbing a stainless riser.

Thanks
Will

Hi All,

I found the source of the problem; the boat has Corsa exhausts with the muffler/baffle plates in. I removed these (following some of the advice on this forum to knock out the welds) and the sound and volume is now exactly as I expected.

Thanks for the advice.

Best
Will

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