Sierra 16-254-1124 EXOFLEX Wet Exhaust Hose 1-1/2 in x 12-1/2 in

Sierra built the EXOFLEX line for wet marine exhaust, where a hose has to shrug off hot exhaust gas, raw cooling water, and constant engine vibration all at once. This is the 1-1/2 inch inside diameter version cut to a 12-1/2 inch length, meant for the short sections between components on a small inboard wet exhaust system. If you're replacing a cracked or collapsed piece between your riser, muffler, or waterlift, this is the part that gets you back on the water.

The construction is what matters on a hose like this. You get an EPDM black cover over synthetic reinforcement plies, with a steel wire helix wound through the wall. That helix is the piece people overlook. Wet exhaust runs under suction as well as pressure, and without a wire helix a soft hose can pull flat and choke the flow. This one holds its round shape under vacuum, so your exhaust and cooling water keep moving the way the engine expects.

It's built to SAE J2006 R2, the recognized standard for marine wet exhaust hose. So you know it's rated for the job and not some general-purpose tubing pressed into service. Temperature range runs from -22 degrees Fahrenheit all the way to 212 degrees, with a 239 degree peak. That cold number isn't just a spec sheet flex. It means the hose stays flexible through winter layup instead of turning stiff and cracking when you splash in spring.

On pressure, you're looking at 60 psi working and 180 psi burst. For a wet exhaust that's plenty of headroom, since exhaust back-pressure lives far below that. The extra margin is why some folks reach for this hose on other demanding runs, like a pump-out line, where the pressure rating actually gets used. Just confirm your routing keeps it clear of chafe points before you commit.

A few things we've learned installing these. First, measure twice. At 12-1/2 inches this is a short section, and there isn't much slack to play with, so a sloppy cut or a fitting that's off by half an inch turns into a weep at the clamp. Second, respect the bend radius. The steel helix resists collapse, but crank it tighter than about four times the inside diameter and you'll kink it. On a 1-1/2 inch hose that means keeping bends gentle, roughly six inches of radius or more. Third, clamp it right. We like 316 stainless T-bolt clamps here. Worm-drive clamps can back off under the constant vibration of a planing hull, and a loose exhaust clamp is not something you want to discover offshore.

One honest note on longevity. That black EPDM cover takes UV hard in an open, sun-exposed engine bay, and after a handful of seasons you may see surface cracking on the outer skin. It's cosmetic at first, but if your install leaves the hose exposed, a wrap of split loom buys you years. In a closed bilge or engine box it's a non-issue.

Where does a short section like this actually show up? Usually it's the jog between a mixing elbow and a waterlift muffler, or the run off the muffler to a transom fitting on a smaller inboard or sterndrive setup. Those spots see the worst of it, hot gas on one side, salt or fresh cooling water on the other, and enough vibration to work a weak hose loose over time. That's exactly the duty this hose is designed for, so it's a sensible part to keep on the shelf if you're the kind of owner who'd rather fix a suspect section at the dock than wait for it to fail on a run. If you're not sure which section on your engine takes this size, your engine manual's exhaust diagram will call out the inside diameter for each leg.

This is the 1-1/2 inch inside diameter, 1-13/16 inch outside diameter size, which fits the majority of small inboard wet exhaust setups. Check your existing hose or fitting OD before ordering, because a 1-5/8 inch fitting is a common mismatch that leads to slippage no clamp can fully fix. Get the size right and this is a straightforward, standards-rated replacement that'll outlast the one you're pulling off.