reverse gate fracture

[omots]

I have a v-shaped broken piece on the reverse gate on a Mercury 40 hp jet. How will this effect performance?

 

[galamb]

It will diminish your forward thrust "somewhat" since instead of focusing the entire jet of water (backwards) some will exit vertically through the breech (water will follow the path of least resistance). How much will you lose - depends on how much thrust is being produced, how big the breech is, and how fast you are travelling in the first place (slower = greater resistance to the rear of the boat).

On the flip side, you will lose some reverse thrust when engaged since you are no longer directing all your thrust back under the hull - some is pushing you "forward" through the breech when the gate is in it's "deployed" position.

Since the efficiency of a jet sucks in the first place when compared to a propped model of similar horsepower, I personally would have the issue repaired. You may not need to replace the entire part - any welder who is adept at welding cast aluminum may be able to "patch" it sufficiently for you.