OMC Exhaust Help

[champ201]

I drilled my 6 holes, then tapped them for 3/4 npt socket head brass pipe plugs. Cross drilled through the socket part of the plugs and wired them so they wouldn't loosen up, fall out and ding anything. They're easy to remove and install, but the snout with a mechanically operated butterfly would be much nicer. Actually, I guess it would be easier to leave the wife at home than deal with the plugs.

[Captain75]

Why not just drill 2 half inch holes in the lower unit below the cavitation plate, sounds just as good and at idle it is quiet? and shouldnt need any jet changes as it wont help performance any, Matt

This is an old thread, but anyway; "Holes under the cavplate" doesn't that make the prop slip?

[frederick55]

This is an old thread, but anyway; "Holes under the cavplate" doesn't that make the prop slip?

They're high and dry when running.

[phantomuk]

My little effort

[phantomuk]

The slot was cut above the cav plate.

[Captain75]

My little effort

Thanks, pictures is the way to go!
I see you have cut out a big "chunk" pointing the exhaust backwards towards the stock slots above the cavplate... I've thought of that aswell, Your own idea?

[phantomuk]

Yeah my own idea, whether or not someone else has done it I would have though so.

[Captain75]

My little effort

Wish more members would post pictures like this!

[mkystybx]

Sorry to hijack this thread but a fair amount of this information relates. I am looking to block or partially block the exhaust flow to the propeller for better hole shot. V8 Johnson with sport exhaust. The volume of flow through the snout seems sufficient but I am worried about reverberation from block off plate to lower 4 cylinders. I think it may make a lean spot at some RPM level. Does anyone have any experience with this?