90 hp johnson bucks at full throttle

[dsujen]

I have a j90tlcur 1987 90 hp johnson. At full throttle is bucks or breaks up like it's starving for fuel. Otherwise it starts easily and runs and accelerates good. I replaced the vro pump with pump #0438556. Engine compression is within tolerances. Do the carb floats need adjustment? I did notice that when I use the electric key choke to start it, gas pours out of the choke solenoid near the red handle.

 

[racerone]

You likely need a new o-ring on the red handle.---Easy fix.---Use a timing light to see if you have an ignition miss at full throttle.---What happens when someone operates the manual fuel pump at full throttle?----And what exactly are the compression numbers ?

 

[ondarvr]

Starving for fuel symptoms are normally smooth surging or slowing down, not rapid bucking, it can run a little rough if its on the rich side though. Electrical problems can act suddenly, like flipping a switch.

 

[emdsapmgr]

Is the red lever on the choke solenoid in the "run" position or in the "Service" position?

 

[dsujen]

I don't know what the red handle position is in. I have to go look. It think it's in the correct position because it runs and starts good otherwise.

 

[dsujen]

What type of electrical problem could it be?

 

[racerone]

Run with a timing light hooked up to # 1 cylinder and take the boat to full throttle.------Does timing light show a steady flashing ?---Repeat with other 3 cylinders.---It could be as simple as a plug lead shorting to a cowling latch , so a run with the cover off should be tried.

 

[dsujen]

I installed brand new spark plug wires yesterday

 

[racerone]

Testing and trouble shooting must be done.

 

[boobie]

Go to cdielectronics.com for trouble shooting procedures.