Finding the right 50 hp johnson outboard motor parts can feel like a bit of a scavenger hunt, especially since OMC (the parent company) went through its changes years ago. If you own one of these workhorse engines, you already know they're incredibly reliable, but they do need some love to keep running smooth. Whether you've got an old 1970s twin-cylinder or a more modern three-cylinder model from the late 90s, the key to a stress-free weekend on the lake is having a solid source for components and knowing exactly what you're looking for.
Start With Your Model Number
Before you even think about clicking "add to cart," you've got to find your model number. I can't tell you how many times people buy 50 hp johnson outboard motor parts only to realize they bought the version for a 40 hp or a different year entirely. Johnson was famous for making small, incremental changes year-to-year.
Usually, you'll find a small metal plate on the mounting bracket. It'll have a string of letters and numbers. If that plate is missing—which happens more often than it should on older boats—look for a "freeze plug" on the engine block itself. It's a small silver disc that usually has the model number stamped right on it. Once you have that, you can look up the specific diagrams so you don't end up with a water pump kit that doesn't fit your housing.
The Most Common Maintenance Items
If your motor has been sitting for a while, there are a few 50 hp johnson outboard motor parts you should just go ahead and replace regardless of how they look.
First on the list is the water pump impeller. These are made of rubber, and they get brittle or "set" in a certain shape if they sit too long. If you start your motor and don't see a strong "tell-tale" stream of water shooting out the back, shut it down immediately. Replacing the impeller is a lot cheaper than rebuilding a powerhead that's melted from overheating.
Next up are the spark plugs. These old two-strokes are notorious for fouling plugs if you do a lot of low-speed trolling. I always keep a spare set in the boat's dry box. They're cheap, easy to swap, and often solve "rough running" issues in about five minutes.
Dealing with the Fuel System
Most 50 hp Johnson outboards use a two-carburetor setup. When these sit with modern ethanol fuel, the gas evaporates and leaves behind a sticky varnish that clogs up the tiny jets. If your motor starts fine but dies when you give it gas, you're probably looking at a carb rebuild.
When searching for 50 hp johnson outboard motor parts for the fuel system, look for a complete carb kit that includes the float. Some cheaper kits leave the float out, but if yours is old and saturated with fuel, it won't sit at the right level, and you'll be right back where you started. Also, don't forget the fuel filter. It's a small part, but if it's clogged with gunk from an old gas tank, your motor is going to starve for fuel at high RPMs.
The VRO System: To Keep or Not to Keep?
If your motor is from the mid-80s or later, it likely has a VRO (Variable Ratio Oiling) pump. This is the system that automatically mixes the oil and gas so you don't have to. It's a bit of a controversial topic among Johnson owners.
Some people swear by them, while others think they're a ticking time bomb. If your VRO pump fails, the motor stops getting oil, and well, it's not a pretty sight. You can find replacement VRO pumps among your 50 hp johnson outboard motor parts suppliers, but they're fairly expensive. Many boaters choose to "bypass" the system and just mix their oil and gas manually in the tank at a 50:1 ratio. It's a bit more work at the gas station, but it gives a lot of people peace of mind knowing the engine is definitely getting lubricated.
Ignition and Electrical Components
If you're getting no spark at all, the problem is usually one of three things: the spark plugs (already mentioned), the ignition coils, or the power pack.
The power pack is the "brain" of the ignition system. If it goes bad, you might lose spark on just one cylinder, or the whole motor might go dead. Testing these requires a multi-meter and a bit of patience. When buying electrical 50 hp johnson outboard motor parts, I usually recommend going with a reputable brand. Cheaper "no-name" electronics from overseas can be hit or miss, and it's frustrating to install a new part only to find out it was DOA (dead on arrival).
The Lower Unit and Propeller
The lower unit is what actually transfers the power to the water, and it takes a lot of abuse. You should change the gear lube at least once a season. When you drain the old oil, keep an eye out for a "milky" appearance. If it looks like chocolate milk, you've got water leaking in, which means you need a seal kit.
Finding a prop is usually pretty easy since many of the 40 hp, 48 hp, and 50 hp models shared the same gearcase. If you've got a big heavy pontoon, you'll want a prop with a lower pitch to help the motor get up into its power band. If you've got a light aluminum fishing boat, you can go with a higher pitch for more top-end speed. Just make sure the splines match up—most of these use a 13-spline shaft, but it's always good to double-check.
Where to Buy: OEM vs. Aftermarket
When you're shopping for 50 hp johnson outboard motor parts, you'll see two main options: OEM (Original Equipment Manufacturer) and Aftermarket.
OEM parts are made by BRP (Bombardier Recreational Products), who bought the Johnson/Evinrude brands. They're generally higher quality but come with a higher price tag. Aftermarket brands like Sierra or MarineEngine offer parts that are often just as good but much easier on the wallet. For something critical like a head gasket or internal engine bearings, I usually stick with OEM. For stuff like fuel lines, impellers, or gaskets, aftermarket is usually perfectly fine.
A Few Tips for the DIY Mechanic
Working on these motors is actually pretty fun because they're relatively simple compared to modern fuel-injected four-strokes. You don't need a computer to diagnose them; you just need a wrench, a screwdriver, and a bit of common sense.
One thing I've learned the hard way: always use a little bit of marine-grade grease on your bolts when you put things back together. Saltwater (and even freshwater) can seize a bolt into the block so tight that you'll snap the head off trying to get it out next year. Also, keep a magnetic tray handy. Dropping a tiny bolt for your 50 hp johnson outboard motor parts into the dark recesses of the lower cowling is a guaranteed way to ruin your mood.
Keeping the Legend Alive
There's a reason you see so many of these old white and green motors still out on the water. They were built during an era where things were designed to be fixed, not thrown away. Even though Johnson isn't producing new outboards anymore, the sheer volume of these engines still in use means that 50 hp johnson outboard motor parts are going to be available for a long time to come.
If you take care of the cooling system, keep the carbs clean, and use good quality oil, there's no reason your 50 hp Johnson can't keep screaming across the water for another twenty years. It might be a little louder and a little smokier than the new ones, but there's a certain pride in keeping a classic machine running perfectly. Just keep your model number handy, stay on top of your maintenance, and enjoy the ride.