If you've spent any time at all around older boat ramps, you've probably seen a johnson 28 spl hanging off the back of a weathered aluminum skiff or a small pontoon boat. It's one of those engines that just seems to hang on forever, defying the logic that says everything mechanical should eventually end up in a scrap heap. While modern four-strokes are quiet and high-tech, there's something about these old two-stroke workhorses that keeps boaters coming back to them.
I've always felt that these motors have a bit of a cult following, and for good reason. They aren't the flashiest things on the water, and they definitely won't win any awards for being whisper-quiet, but they have a reputation for being nearly indestructible if you treat them halfway decent.
What Does the SPL Actually Mean?
If you're new to the world of Outboard Marine Corporation (OMC) engines, you might wonder what that "SPL" stands for. It's short for "Special." Now, in marketing speak, "Special" usually means something fancy, but in the world of Johnson outboards back in the day, it actually meant the opposite. The johnson 28 spl was a budget-friendly version of their standard 30-horsepower motor.
To keep the price down, Johnson stripped away some of the "luxury" features. The biggest difference was the lack of oil injection. While the higher-end models had VRO (Variable Ratio Oiling) systems that mixed the oil and gas for you, the 28 SPL required you to do the mixing yourself in the tank. Honestly, looking back on it, that was probably a blessing in disguise. Those early oil injection systems could be finicky, and plenty of motors met an early grave because a pump failed. With the 28 SPL, as long as you can remember to pour a pint of TC-W3 oil into six gallons of gas, you know your engine is getting lubricated.
The Simplicity of a Two-Stroke Workhorse
There is a certain beauty in the simplicity of an engine like this. It's a twin-cylinder, two-stroke design that doesn't require a computer to diagnose. If it isn't running right, it usually boils down to one of three things: spark, fuel, or compression.
I've spent many Saturday mornings with a socket set and a can of carb cleaner working on these types of motors. Everything is accessible. You don't have to pull half the engine apart just to get to the spark plugs or the carburetor. This makes the johnson 28 spl a favorite for the DIY boater who doesn't want to pay a mechanic eighty dollars an hour to do something they can do themselves in their driveway.
Fuel Systems and Modern Headaches
One thing you'll hear anyone talk about when it comes to these older outboards is the fuel. These motors were designed long before ethanol became a standard additive in our gasoline. Ethanol is basically a death sentence for old rubber fuel lines and needle valves.
If you own a johnson 28 spl today, you've got to be diligent. Most people I know who run these old gems swear by non-ethanol "rec gas" if they can find it. If you can't, a good fuel stabilizer is non-negotiable. I've seen those tiny carburetor jets get gummed up after just a few weeks of sitting with bad gas. It's a minor annoyance, but a small price to pay for a motor that otherwise refuses to quit.
The Famous 50:1 Mix
As I mentioned earlier, you're going to be mixing your own fuel. The standard ratio is 50:1. That's roughly 2.6 ounces of oil per gallon of gas. There's a specific smell to a johnson 28 spl when it first fires up on a cold morning—that blue cloud of smoke and the distinct "pop-pop-pop" idle. Some people hate it, but for a lot of us, it's the smell of a fishing trip about to happen. Once the motor warms up, the smoke usually clears out, and it settles into a steady hum.
Performance and Power-to-Weight
For a motor rated at 28 horsepower, these things punch surprisingly hard. Because it's a two-stroke, it's relatively light compared to a modern four-stroke of the same power. This is a big deal on a 14-foot or 16-foot aluminum boat. You want as much power as possible without the transom sitting three inches deep in the water.
The johnson 28 spl has enough torque to get a decent-sized load on plane without much drama. I've seen them used on everything from small bass boats to "party barges" that probably should have had a 50hp on them. They just keep chugging along. The gear ratio and the prop selection available for these motors mean you can really tune them to fit whatever hull you're running.
Reliability in the Real World
You often hear people call these motors "bulletproof." While nothing is truly bulletproof, the 28 SPL comes close. The ignition system is pretty robust, using a power pack and a stator that usually last for decades. When they do go out, they are easy to replace.
The cooling system is equally straightforward. It uses a standard rubber impeller located in the lower unit. As long as you don't run the motor through a sandbar or let it sit in the mud, that impeller will happily pump water for years. That said, it's always smart to change it every two or three seasons just for peace of mind. There's nothing that ruins a day on the lake faster than seeing that "telltale" stream of water stop flowing from the back of the engine.
Common Issues to Watch For
No motor is perfect, and the johnson 28 spl has its quirks. Since many of these engines are now thirty years old or older, you have to expect some wear and tear.
One common thing I see is the starter solenoid going bad. You turn the key and get nothing but a click. Luckily, it's a cheap part and takes about ten minutes to swap out. Another thing to look at is the lower unit seals. If you notice your gear oil looks like chocolate milk when you drain it, you've got water getting in there. Replacing the seals isn't the most fun job in the world, but it's a lot cheaper than replacing the entire gearcase because of rust and heat.
Also, keep an eye on the motor mounts. Over time, the rubber can get soft or brittle, which leads to more vibration. If the motor feels like it's trying to shake the boat apart at idle, that's usually your culprit.
Finding Parts for an Older Johnson
One of the best things about owning a johnson 28 spl is that parts are everywhere. Because OMC made so many of these (and the 20, 25, and 35hp versions that share many components), you can find almost anything you need. Whether it's a new carburetor kit, a replacement prop, or even internal engine parts, there's a huge market for both OEM and aftermarket replacements.
I've never had an issue finding what I needed online or even at local marine shops that have been around for a while. There's a massive community of enthusiasts too, so if you run into a weird problem, a quick search on a forum will usually give you the answer in minutes.
Is It Worth Buying One Today?
If you're looking at a used boat and it has a johnson 28 spl on the back, don't let the age scare you off. If the compression is good—ideally over 100 PSI and even across both cylinders—you've likely got a motor that will last another ten years with basic care.
Sure, it's not as fuel-efficient as a brand-new fuel-injected four-stroke. And yeah, you have to deal with the oil mixing and the noise. But you're also not paying five or six thousand dollars for a new motor. For a fraction of that, you can have a reliable engine that you can actually fix yourself if it ever acts up.
In the end, the johnson 28 spl represents an era of marine engineering where things were built to be simple and durable. It's a "honest" motor. It doesn't pretend to be something it's not. It's just a solid, dependable piece of machinery that wants to help you catch some fish or enjoy a sunset on the water. And honestly, isn't that what boating is supposed to be about anyway?