CONTINUOUSWAVE

My 2004 DAUNLTESS 16 was pre rigged with a Mercury 90-HP ELPTOSW two-stroke-power cycle engine serial number OT942695.

The gear case has a defect.

I found a replacement gear case.

I have learned that my Mercury 90-HP engine is [actually] a model LL with a 22.5-inch lower unit that was only produced for Boston Whaler and only for a few years. The gear case is part number 1667-9011J15.

The 2004 DAUNTLESS 16 transom from the upper edge to the centerline of the keel measures 22.5-inches.

After searching yards and marinas and a established Boston Whaler dealers, [I deduced] this is an obsolete gear case, no longer available as a unit, but some seals and bearings are still available.

Q1: Can a 2004 DAUNTLESS 16 be re-powered an 25-inch shaft engine?

Q2:Can a 2004 DAUNTLESS 16 be re-powered with a 20-inch shaft engine?

Q3: Will the performance of a 2004 DAUNTLESS 16 be satisfactory with a 25-inch shaft engine?

Q4: Will the performance be satisfactory with a 20-inch shaft engine?

The [2004] Boston Whaler catalog gives transom height as 20-inches.

You should not install a 25" shaft on this model as it is designed for a 20" shaft.

What you can do is mount the engine 3 or 4 holes up, the top bolt in 4th or 5th hole counting down from the top of the transom, depending on the prop you use. The bolt holes in the engine are for installing at different heights, based on hull.

Take a flat board, level or ruler and lay it on the bottom of the hull sticking out past the transom. Measure from the top of the board/level/ruler up to the bottom of the plate/fin above the prop. This measurement should be 1-1/2 to 2".

Thank you for your response Phil T.

I have found a matching aftermarket gear case. Engine will be at the original mounting position.