How Do I Change The Gas Filter On A 125 Horse Mercury Outboard

Sometimes I encounter someone'south boat that will simply not continue the fuel primed upwardly. Which becomes a hassle and you take to pump the primer bulb every fourth dimension yous shut the engine off! And then what do you lot do, you lot ask?

Why Does My Outboard Lose Prime? Outboard engines lose fuel prime because of an air leak in the fuel system. Somewhere between the engine and the fuel tank.

Here are the best and quickest ways to troubleshoot and resolve this issue!

What Are The Symptoms of An Air Leak?

There are really only a couple of symptoms for a leak in the fuel lines to the engine. Either the engine randomly runs out of fuel and dies. Subsequently turning the engine off and letting information technology sit down for a couple of minutes, you lot have to prime the primer seedling up again.

Or in that location is a running result, where the engine is not getting wide-open throttle and spits and sputters when you lot become upwards and going. Aerated fuel can cause a running outcome, but this can become catchy and send you off on a rabbit hunt for a trouble that is mayhap not fifty-fifty related! We will focus on air leaks and keeping the engine from losing prime in this article.

Understanding Different Engines

There are different causes to this depending on your engines. If y'all have 4-Stroke outboards or fuel injected motors, so this will be a mutual issue acquired by an air leak. four-Stroke engines or fuel-injected engines will generally never lose prime. The engines store fuel in either a VST or an FSM. (What is an Outboard FSM or VST?)

With a certain amount of fuel stored in the VST, the engine will fire up and run correct when you hitting the central switch. And then the electrical fuel pumps volition begin sucking fuel out of the tank, and you lot don't really notice if there is a leak or not. That is unless it is a pretty bad leak!

2-Strokes on the other manus, that is a different story! Carbureted engines will mostly have this problem and it will exist a lot more noticeable, in a shorter period of time. Mostly, if there is no issue, you can turn the engine off for a couple of hours and never lose prime. Merely if y'all let the engine sit down overnight, you have to prime it in the forenoon.

Most of the fourth dimension considering of the carburetors design, the fuel tin can siphon bank into the tank and you will have to prime number it upward before every cold or next twenty-four hours showtime.

Visually Inspect The Fuel Lines

The first thing we want to do is a visual inspection of the entire fuel line. Starting at the engine. Follow along the fuel line moving it around and looking at it.

Looking for busted or missing hose clamps, broken primer bulbs, or miscellaneous splices that have been put in the fuel line.

Extensions in fuel lines, to salve erstwhile fuel hoses, create weak spots. For every identify that the hose is cut and continued to something, this is a location for a leak!

Check over the boat fuel filter and its fittings. Making sure the fuel filter is not rusted through or is loose enough to let air to get into the system, causing the fuel to leak from the engine, dorsum down into the tank.

Where To Start Troubleshooting

We will desire to offset our troubleshooting process past obtaining a minor say one-foot long clear hose and a coupling hose barb, that is the same size diameter every bit your fuel line. We demand to take off the engine cowling, then locate where the fuel line is coming into the engine. Find the first place information technology connects to, generally to a fuel filter, and disconnect the fuel line there.

Insert the clear hose into the fuel line, prime upwards the engine, and showtime it upwards! Let it run for a picayune while and carefully sentry the fuel passing through the clear hose.

If yous come across a ton of air bubbling coming from the boat fuel tank side of the hose, so we are hot on the trail to solving this issue!

Follow The Bubbling!

At present, remove the articulate hose from the fuel line and reconnect it the way it should exist. Tighten the clamp or zippo tie, and move down the fuel line towards the fuel tank. When you lot hit the next coupler, primmer seedling, or connection betoken on the hose. Reinstall the articulate hose at that place and retest for more bubbling.

You tin too skip a skillful portion of this process if you lot desire to go directly to the tank and exam before following the bubbles. If you suspect the tank, and then get ahead and straight connect the clear hose to the pickup tube hose barb.

Retest and see if yous have bubbles. If there are bubbling there, and then there is something going on with the pickup tube or the fittings there at the fuel tank.

If there aren't whatsoever bubbles, then go ahead and go dorsum to the kickoff where we started. And move down the line with the clear hose, until you hit the point where the bubbles end.

Near of the fourth dimension, with the visual inspection or process of moving that clear hose downward the line. Y'all will find a broken hose affront plumbing fixtures or cracked pick up tube.

I've even seen corrosion on the fuel filter bracket and an air leak on the dorsum of the bracket. You would never exist able to tell from only looking at it. But as I moved the clear hose along the line. Smash! Bubbles on one side, and straight solid fuel on the other!

Fix-It & Get Information technology Washed!

Now that y'all take located the leak, set up information technology! There is non much more than to it than that! Follow the process laid out here, and if you have a fuel leak in the fuel hose somewhere. You will find it and then cut the end of the hose off and put a new clamp on, change out the fuel filter, the subclass, run some new fuel hose, and get back on the h2o!

Something To Know About Fuel Hoses.

Know that non all fuel lines are made every bit! If you have blue, or gray fuel hoses. Brand a notation and look into the hose to see if the inside of the hose has separated from the exterior of the hose. Blue and gray fuel lines, (mostly the blue lines), are known for separating.

The near common crusade of this is ethanol, which will speed up the deterioration. But the hoses themselves are merely inexpensive!

If the inside separates from the exterior when the fuel pump kicks on or is running, it tin can suck the inside liner shut and the engine volition run out of fuel. It tin besides cause all kinds of running issues and problems that can drive yous nuts!

I would propose getting rid of those hoses and replacing them as soon every bit you tin can. Ride them out when you tin, but take note that this volition eventually happen to the hoses.

Properly Priming a Primer Bulb!

Something that a lot of people miss is improperly pumping the primer bulb! Yes, in that location is an incorrect way of priming the primer bulb! Who would have known?

If the primer bulb is held horizontally. Then most of the time, it will not prime anything at all! You can pump and pump and pump until your hands are shaking, but be it known, you ain't pumping goose egg but air!

Belongings the primer seedling vertically is the proper mode to utilize the primer bulb and ensures that if in that location is fuel shut, it volition suck it upwardly.

How To Prime Upwards Fuel When Primer Bulb is Air Locked

Another thing to know about primer bulbs is that if the fuel leaks to far dorsum into the tank. The primer bulb can't suck it upwards without removing it.

If the primer seedling airlocks and won't seem to get whatsoever fuel:

Disconnect the fuel line from the engine side of the bulb. With the arrow pointing to the side where you pulled the hose off.
Hold the primer bulb vertically with the pointer facing the sky and squeeze the primer seedling until it is completely collapsed.
And so, stick your finger on the hose barb.
Let go of the primer seedling.
Then, as you squeeze it again, remove your finger and apace put it back on the barb when the primer bulb is completely collapsed.
Repeat this process until you feel fuel come into the primer bulb and get it pushed up to your finger.
And then reconnect the fuel hose on the seedling and prime that bad male child upward!

Hint: If you pump and pump and pump and never get whatever fuel out. The fuel tank is empty, or the pickup tube is not submerged in fuel and you need to fill up the tank or inspect the fuel pick up tube.

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