Hello all,

I have a 1979 Martini, and for some reason the exhaust tips are at water level. Every time we go to the bay, water will enter through the exhaust into the engine, and hydro-lock the boat. A few mechanics have told me I am crazy for wanting to do this, but I was thinking, couldn't I install metal flaps inside the exhaust pipe so that if water gets in through the rubber flap, the metal ones will stop it?

Any help/tips on this would be great, thanks!

A secondary flap would be a great idea as Mercruiser states if the exhaust tip is within 12" of the water line you should have internal and external flaps. I don't know your whole system but this would be a great start

It is a very weird system. There is nothing stopping the water from hitting the motor except the rubber flaps, which seem to float.....

Both metal internal and rubber flaps. I would steer clear of those '' mechanics ''


John jr

Yes, both andThere are different external flaps that inboard ski boats use that help keep them from 'floating' up as you state.

Thank you!

where could i get a universal type flap from?

Hardin answered you first correctly, so give them a shot first.

If they don't have them type into your search browser "marine exhaust flappers" , click on pictures, find what you want, and then click. There should be a bazzillion to chose from.

i got one from hardin marine and it was too big... they dont have any smaller ones 410-280195 is the part number... wont fit inside a 4 inch hose... west cost offshore has one that looks like it will work... im calling first cause i dont wanna lose money on "2 day shipping" and have it come 4 days later again... and get charged a restocking fee of 15%

hjkl