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1989 Johnson 110 Fuel Issue

jmancrafter5

New member
Just bought this motor a few days ago. Put it on my boat and it runs great. i can out it at full throttle and it runs great for about 30 seconds before the motor runs out of gas and it dies. What could be causing this?
 
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Test run with another tank and hose.-----Also get an assistant to operate the manual fuel pump as a test.----Might consider posting compression test results too.----Fuel pump is driven by crankcase compression pulses.----Cylinder compression may help diagnose fuel pump operation.
 
Compression for all four cylinders is all right around 100. I think cylinder 4 had 97 psi and that was the lowest. I ordered a 3/8" fuel line to replace the 5/16th one and ill be testing that tomorrow night. If someone pumps the bulb a few times then it works fine at full throttle. It runs perfectly fine with anything other than full throttle. I was doing some reading as well. Some people on other forms were saying upgrade to a bigger line because the engine is needing more fuel than what my fuel line can give it. I will also be trying a different tank tomorrow night.
 
V-6 motors need 3/8" line !----If your gauge is accurate you need to pull bypass covers ( 6 screws each ) to inspect pistons and rings !
 
theCoachman here,
sorry if I'm posting in the wrong place, my first time here!

Just bought a 72 glasstron with a 100 horse johnson 4 cylinder. I have a ton of questions!

The first being is this motor a 2 or 4 stroke (model # 100 esl72R)
2 if it's a 2 stroke, what would the fuel mixture be?
3 is there a way to get this unit into neutral manually? Shift lever is in neutral position but the prop turns when you hit the key.

Would appreciate any and all help!

Thanks in advance for your patience and assistance
 
No such thing as a 4 stroke Johnson in 72.-----Mix at 50:1.-----When the motor is NOT RUNNING it will always be in forward gear.-----If the lower unit is in good condition it shifts to neutral after one turn of the flywheel.----No you can not shift it manually.
 
Just bought this motor a few days ago. Put it on my boat and it runs great. i can out it at full throttle and it runs great for about 30 seconds before the motor runs out of gas and it dies. What could be causing this?

Weak fuel pump
Clogged fuel pump inlet screen
Fuel restriction
Blocked or kinked fuel line
Defective primer squeeze bulb @ fuel line
Carb float not dropping properly
Water separator fuel filter clogged or full of water

As stated above, run on a test tank first. A gallon of fresh mixed fuel with a new hose and bulb dropped into it works well.

1. If it runs well, then the restriction is in the boat's fuel system.
2. If it still boggs down, the problem in in the motor's fuel system, probably the fuel pump. Check the inlet screen, if a standard pump. Also check that the pulse line isn't loose, cracked or split.

Hope this helps.
 
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