1650 Sylvan Jet project

bassboy1 · Oct 2, 2012

I've been busier than ever, so I haven't really posted many projects recently, but here are a few pictures of some upgrades I did to a customer's 1650 Sylvan w/ Merc 40/25 jet.

Here's what we started with. The original plywood transom was shot, and the transom had a noticeable curve to it. Also, the boat had a bit of a stern heavy issue, so a set of pods were to be installed.

After pulling the motor, removing the aft seat boxes, and the original transom plywood, we find a mess of corrosion. This is exactly why plywood and aluminum shouldn't be sandwiched together.

Fortunately, as this was a freshwater boat, the corrosion had merely formed shallow poultice cells on the surface, and hadn't formed deep pits except around one of the handle bolts. As a result, a coarse Scotchbrite disc and an acid washing brought most of the transom back to clean aluminum, leaving a small circle of pits to grind out and weld back.

Next in the deconstruction was the removal of the center seat pods. These weren't providing any functional storage to the owner, and made moving about the boat fairly tough. We will be reinstalling a smooth well deck to prevent tripping over the floor ribs.

bassboy1 · Oct 2, 2012

We'll start now with the building of the new transom.
Perimeter frame.

Welded in bushings for engine/jackplate mounting bolts.

Additional bracing as required for bolt on pods, stern handles, and other bolt on items. Flat bar in the middle is tapped for the knee brace.

Dry fit.

New inside panel installed.

bassboy1 · Oct 2, 2012

And the knee brace - slightly modified for new transom (16" tall instead of 10).

CMC manual jackplate mounted. Customer provided this unit. It is rated for a 300hp V6, so we'll see if it holds up to the 25 jet. :lol: Sometimes you just have to push the engineering limits of a product. :lol:

Now, we can reinstall the engine.

While we're on the subject of the transom, we'll discuss the pods. On the mod vee boats, the factory made pods leave one with a dilemma - match the bottom of the pod to the bottom angle of the boat, and have it slant inward on the top, or mount it level on the top, loosing some flotation at the bottom. In this case, we built the pods to fit the boat, and as a result, we didn't have to pick a tradeoff. Also, boarding steps were incorporated for the owner's four legged furry friends.

These pods will be installed 1" from the bottom of the hull, and taper upward an additional inch over the length. On this particular boat, the extra flotation at rest is what is needed - on plane the boat already balanced well, so we didn't want to add too much additional planing surface.

Initial tackup.

After passing a pressure test, it is time to attach them to the boat.

bassboy1 · Oct 2, 2012

Now, simply reinstall the stern seat pods.

Customer then decided that we should go ahead and add in a flat floor for the fuel tank. A little brake work, and here we are.

Fuel tank lid. This alone turns the back bench seat into a comfortable casting deck.

Moving forward now, we install a well deck. Owner didn't want side panels, so instead we coped around the ribs. A small bulkhead was made to keep leaves, baitfish and other stuff from finding it's way under the rear bench seat.

The same was done for the bow deck.

The owner also wanted a hatch to put 2 batteries up in the bow. We only had room to place them end to end, so that is what was done. Here is the start of the drop in storage hatch.

And the finish.

And here it is set in place. Though it looks like it is resting on the upper lip, there is actually a support frame underneath, which it is attached to. The upper lip provides a coaming for water coming off the top of the hatch, and not much else.

bassboy1 · Oct 2, 2012

Then, we fabricate/install the lid, and run the conduits. One goes forward for a future trolling motor plug, the other heads to the side of the boat for assorted accessories.

Lastly, I installed a set of longer bunks, and new fenders.

After

And here is the finished rig.