Johnson outboard fuel pump problems

Outboard fuel pumps rarely fail and diagnosing a fuel problem involves checking other components that can be easily mistaken for a bad check valve or. You might notice sputtering or misfiring before the engine cuts out completely.

The primer bulb is a manual fuel pump of sorts.

Johnson outboard fuel pump problems. When the outboard fuel pump is bad it operates similarly to when the boat runs out of fuel. You might notice sputtering or misfiring before the engine cuts out completely. To help you get back on the water we will talk about how the outboard fuel system works discuss ways to troubleshoot the issues and give you some expert pointers along the way.

Re-start the Johnson outboard and allow it to run at a high speed. If the motor still falters or sputters during this high speed it means that the fuel pump is bad and should be replaced. Apr 7 2011.

Rebuilt water pump carbs and changed spark plugs. Put the boat in the water to test it out and when you give it FULL throttle 5000 rpm it falls to its face. Thought it might be a bad full line.

Changed out the full line and filters as well as the primer ball same issue. Toby The fuel system on that motor is non-trivial. You would benefit from a genuine Johnson Service manual.

That motor has an OMS pump to mix oil with the gas and a vapor seperator and pump to help the OMS pump get only liguid gasoline. As the others said idle and acceleration problems are likely clogged carbs fuel supply is OMS or vapor seperator air leaks restricted filters etc. You can check this by pumping the primer bulb until it feels hard.

Fuel should travel easily from the tank all the way to the pump. Your outboard fuel filter located just before the fuel pump should be full. With the engine off and the cowl cover removed remove.

How to Repair Johnson or Evinrude VRO FUEL PUMP Replacing the Diaphragm Removing outboard fuel pump. The diaphragm was cracked and the motor was not getting. One of them is the constant worry of having the VRO oil pump go out on you.

Many boaters elect to bypass a Johnson or Evinrude oil pump. There is a ton of information in the Internet on how to do this. The problem with this is that you still have a VRO oil pump acting as a fuel pump.

In my opinion this is a failure point waiting to happen. Fuel Pump Rebuild Kit for Johnson Evinrude Outboard. A fuel pump rebuild kit is needed every so often with outboard motors.

The inner rubber diaphragm can develop cracks or pin holes that effect proper fuel flow and inner check valves and springs can break causing complete pump failure. He will check out the carbs while it is apart in case the fuel pump has been throwing crap into the fuel. He will also install a real fuel filter to supplement the little one built into the motor.

Finally he will check the fuel tank pick up just in case that is cracked and letting air into the line. Fuel system problems The most likely problems to beset older two-stroke outboard engines are with the fuel system. Modern fuels have a shelf life of only a few months especially when mixed with two-stroke oil with the fuel leaving a black varnish or gum on the inside of the carburetor when it.

The outboard fuel pump has a sensitive diaphragm that receives a suction signal from a piston cylinder so the pump can deliver fuel. If the cylinder has a leak the pump pulse signal will not be strong enough to send the proper amount of fuel to the cylinder. Outboard fuel pumps rarely fail and diagnosing a fuel problem involves checking other components that can be easily mistaken for a bad check valve or.

Possible problems with the fuel line can be the connectors the bulb and excessive wear. Ensure the connectors are clean and properly fastened. The bulb should after a few pumps be firm to the grip.

Your outboard may be stalling running out of fuel due to three issues. Either the lift pump has failed the boat is out of fuel or there is an air leak or blockage somewhere in the fuel lines running fuel from the tank to the engine. One thing to check would be your primer ball.

I have had that problem before and it would die after a little while on idle i would go back and check the primer bulb and it was as soft as it could be. Pumped it up and it was good the rest of the day. It could be a slight crack or weathering in the bulb or the hose.

I would check that first then try some differnt fuel. After running some new fuel through there. Johnson J50TLCEC start problems.

I have a 1989 Johnson 50Hp It has been converted from the original VRO fuel pump to the standard pump part number 438559. All was running fine until the fuel out snapped off was a plastic nipple I contacted the dealer who sent me a new pump with the brass nipples on fuel out and pulse both pumps original parts. All you need to know about your outboard engine issues and good advice from your fellow boaters.

From outboard engine and electrical and electronics systems to engine and alarm issues tilt and trim issues this is the place to find information. So many queries and questions from frustrated Johnson outboard owners. Fuel Pump Problems.

The primer bulb is a manual fuel pump of sorts. Its purpose is to initially pressurize the fuel system and once the motor starts the motor takes over using internal engine pressure alternating vacuum inside the block to activate the fuel pump sucking fuel from the tank. In the early 1960s OMC changed the design to use what is still common today a pulse activated fuel pump.

A pulse activated fuel pump works based off the pressure pulse created by the revolution of the crank case. This pressure pulse excites a diaphragm in the fuel pump which in turn move fuel between chambers in the pump that are controlled by a one way valve so the fuel doesnt go back. The first 2 years of production of this model 19651966 used a different old style fuel pump 0380016.

This fuel pump was used on other motors as well like at least the 95hp up until 1967 which is shown by clicking HERE. Repair kits seem to be non-existent for these older versions however gaskets and screens still are. Because the fuel pump is a self-contained unit that cant be dismantled or serviced youll need to replace it with a new fuel pump assembly.

However before buying a new fuel pump check the pumps electrical connections and that the pump is getting power. The problem might just be a.