Most Common Problems with Yamaha 250 Outboard (Troubleshoot)

Yamaha has been impressing you guys with their outboards since the 70s. But with its 4-strokes, it amped up a notch! The engine can handle the harshest of environments thanks to Yamaha’s technology.

In this article, however, I will give you some common cons the engine comes with. Hopefully, this will throw light on your final decision of outboard shopping. 

A Quick Overview to Yamaha 250 Outboard Issues and The Reasons Behind Them:

Yamaha 250outboard has an innovative plasma-fused sleeveless cylinder design. To add to it is a full-electronic control of the throttle valve. 

The big-bore V6 outboard has a capacity of 4.2 liters. The offshore outboard has the highest capacity of its kind. Meanwhile, it is as light as just 253kgs.

All digital electronic controls and variable camshaft timing are to be mentioned!

With that, there are still some problems like these:

1. Boat not engaging/turning over. Faulty Electric System,
Battery Problem.
2. Engine dies/does not startFaulty Fuel Line,
Faulty Fuel Connection,
Engine Oil Level Down,
Faulty Spark Plugs,
Faulty Primer Bulb.
3. Excessive VibrationFaulty Propeller,
Improper Mounting of Motor.

Common Problems with Yamaha 250 Outboard and Possible Solution:

1. Boat Not Engaging/Not Turning Over

Yamaha 250 outboard has all electrical controls. So the boat not engaging enough is a common problem. 

You will notice the engine being rough at low RPMs. Low RPMs can range from (600-1900). However, the boat should be fine on the plane. 

The boat may not start. Notice that the starter engages but the boat does not start. Often when you’re holding the key at the start, the boat turns over a couple of times but doesn’t start. 

Reason for the Problem:

  • Faulty electric system. The main fuse is probably blown.
  • Damaged battery. Either end of the battery cables may be corroded. A bad cable or a bad battery switch may also be responsible. If the battery voltage is less than 12V, it indicates a bad battery. 

Possible Solution:

Check the main fuse for possible damages. If a blown-out fuse exists, replace it. 

If you find a damaged battery, battery cable, battery switch must be changed. 

To fix this, things You’ll Need:

  1. Screw Driver
  2. Pliers
  3. Wire Bristle Brush
  4. Rag
  5. Water
  6. Baking Soda

Troubleshoot 1: Changing the Fuse (if damaged)

Unscrew the electric cover. Remove it. With the pliers, remove the fuse holder. Now, replace the fuse with the same amperage. 

Troubleshoot 2: Clean Battery

From the housing of the battery, disconnect the negative and positive cables. Then carefully remove the dirt off the battery. The debris collecting on battery terminals should be scraped off with a wire bristle brush. Water and baking soda (1 tablespoon) can be used to clean other debris off the battery. 

With a dry, clean rag, dry off the cleaned parts of the battery.

Troubleshoot 3: Replace Damaged Battery or Battery Parts

After cleaning the battery, if you find corroded cables, switches, then replace those. If you take the voltage test and find the voltage fluctuating from 12V, change the battery. 

Then recharge the battery for use. 

2. Engine Dies/Does Not Start

Of course, check the fuel tank first for fuel amount. 

If the engine is filled with fuel, then check the fuel lines. Symptom of fuel line leakage includes a hard starting engine. More symptoms include fuel leaks, fuel smell from the exhaust, etc. 

A loss of pressure in the fuel pump may point to faulty fuel connections. The motor surges at high speeds. It may also cut out. 

Bad spark plugs cause loss of engine power, decreased acceleration, or problems starting the engine. 

You may notice the engine losing prime or fuel randomly emptying when the primer bulb is bad. 

Reason for the Problem:

  • Fault in the fuel line connecting Yamaha outboard motor with the fuel tank. 
  • You might find corroded fuel connections. This makes the fuel tank lose pressure. 
  • Engine oil level should be between the marks L and H. Below L or above H is problematic. 
  • Burnt or cracked spark plugs.
  • Broken or cracked primer bulb.

Possible Solution:

As faulty fuel lines are an issue, change faulty fuel lines. After that check for corroded fuel connections and change them.

Keep proper engine oil levels. Replace faulty spark plugs. Replace the broken primer bulb. 

Things You’ll Need:

  1. Wrench.
  2. Screwdriver.
  3. Needle-mouth Pliers.

Troubleshoot 1: Changing Fuel Lines

Fuel lines usually require professional help. But you can change the lines this way:

  • Take the old bulb off the fuel line with a screwdriver. 
  • Get a new bulb and fuel line. Insert the fuel line to the side of the bulb, opposite to what goes to the outboard. 
  • Secure the end with a clamp.
  • On another end of the fuel line, attach a connector. Choose the right connector to go with the tank. Secure with a clamp by screwing with a screwdriver. 
  • On the other end of the bulb, attach another new fuel line. This line will go in the outboard. 
  • Now attach the respective fuel lines. The outboard one with the outboard, the fuel tank one with the fuel tank. Secure the lines. 

Troubleshoot 2: Re-establishing New Fuel Connections

Replace the connections with the help of a professional or an expert. This can be done while changing fuel lines.  

Troubleshoot 3: Maintain Proper Engine Oil Level

  • Make the motor upright. 
  • Then take out the oil filler cap and the dipstick. 
  • Wipe the dipstick and reinsert it. 
  • Take out the dipstick again and check the oil level. 
  • Fill the oil up to ‘H’. On the contrary, if there is oil above the ‘H’ level, then remove the excess oil. 

Troubleshoot 4: Replace Faulty Spark Plugs

  • With a wrench, take out the spark plug. 
  • Replace the spark plug by following an instruction manual. It is a sophisticated process so take extra care. Consult professionals if you can’t do it yourself. 
  • Maintain the spark plug gap. 

Troubleshoot 5: Replace Broken Primer Bulb

  • With needle-mouth pliers, press the tabs behind the primer bulb. This will pop out the primer bulb. 
  • Take the new primer bulb and put it in the bulb housing. Use a screwdriver to put it in the primer housing. 

3. Excessive Vibration 

The boat tends to vibrate at low speed. 

Reason for the Problem:

  • Faulty propeller
  • Improper mounting of the motor

Possible Solution:

Change the propeller. After that, if the problem persists, fix the mounting position of the motor. 

To fix this, things You’ll Need:

  1. Pliers
  2. Screwdriver

Troubleshoot 1: Changing the Propeller (if damaged)

  • Unscrew the bolts on either side of the propeller. 
  • Take off the propeller.
  • Replace it and secure it with bolts.

Troubleshoot 2: Fixing the Mounting Position

Take out the engine by unscrewing it from the housing. Find the middle hole to screw in the engine. 

What Majority of the Users Feel About Yamaha 250 Outboard?

This is the real deal! Every single person owning a Yamaha 250 seems to be swoon by it! 

The performance along with the light-weight feature impresses everyone. Moreover, their customer service is reliable too! The engine runs smooth as reported by people!

Clean chit from boaters!


The Yamaha 250 Outboard is a steal in terms of 4-stroke outboards. It is lightweight and enduring. On top of that, cutting-edge technology provides the best performance.

In terms of expenses, the engine is preferable. Moreover, it is not laden with many common problems. 

So, my final verdict is to go for the engine if you want a good 4-stroke 250 HP.

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