2004 Johnson 90 HP problems

[Leeman Seaman]

Hi, new here need help
I have a 2004 Johnson 90Hp V4. I gassed up last week, went about 5 miles downriver and the motor started to die, missing, rattling, would not get over 3800 RPM. Thought it was a fuel problem, hooked up a remote tank with gas from a different source. It ran good for about 15 minutes then started sputtering again. Local dealer said it has to be a power pack problem. It ran good before the refuel, ran good for a while after new fuel, but had the same problem. Question is ??? Coils, Powerpack, something else???? While running (idling) pulled spark plug leads and no noticeable loss of rpm, could not identify a bad cylinder. Is there a way to check the powerpack, coils, ect before I start guessing and start replacing various parts. It seems as though the problem as spontanious(electrical) not fuel, if it was fuel it shoud bog and die????The miss is really quick, my tractor mechanic buddy says, it bogs really fast(not a fuel problem), although it seems to idle just fine. I there any tests that I can do to check the coils, stator, power pack or whatever to eliminate whatever is bad before I replace the power pack(300.00). Any help would be appreciated.
Thanks, Lee

 

[angus63]

Re: 2004 Johnson 90 HP problems

Not certain, but does your motor have S.L.O.W feature? If so, the powerpack will limit rpms to about 3800rpm initially down to 2500rpm finally if high heat is detected. Are you sure your alarms are hooked up and functioning?

 

[Leeman Seaman]

Re: 2004 Johnson 90 HP problems

The motor does have the SLOW feature. All alarms hooked up. Pumping Oil (marked tank)

 

[HighTrim]

Re: 2004 Johnson 90 HP problems

Do you know if it is a quickstart model?

 

[HighTrim]

Re: 2004 Johnson 90 HP problems

1. Use a temperature probe and verify that the engine is not overheating.
2. Disconnect the tan temperature wire from the pack and retest. If the engine now performs properly, replace the temperature switch.
3. Make sure the tan temperature switch wire is not located next to a spark plug wire.

 

[HighTrim]

Re: 2004 Johnson 90 HP problems

1. Check the stator and trigger resistance and DVA output as given below for both banks:
Wire Color Check to Wire Color Resistance DVA Reading
Brown wire Brown/Yellow wire 450-550 150V or more Connected
White wire Blue wire 38-42 0.6V or more Connected
White wire Green wire 38-42 0.6V or more Connected
NOTE: Also check the DVA readings to engine ground from each brown wire and compare the readings. If one wire reads low while connected to the pack, swap the connections and see if the low reading stays on the same stator wire. If it does, the stator is bad.
2. Check the DVA output on the orange wires from the power pack while connected to the ignition coils. You should have a reading of at least 150V or more. If the reading is low on one cylinder, disconnect the orange wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack.

 

[Leeman Seaman]

Re: 2004 Johnson 90 HP problems

Hightrim,
Thanks for the reply. I may have a dumb question though. Test with the motor running or not???
Lee

 

[Leeman Seaman]

Re: 2004 Johnson 90 HP problems

I tried the tan temp switch wire, it ran good for ten minutes and then started cutting out again, so not the switch. Took apart the powerpack and coils, the wires were different colors than those listed above.
Here is what I have going into the powerpack, looking at the back of the engine:
Left side plug going into harness:
black/yellow-tan-white/black-yellow. 4wires
Wire in center of pack going to flywheel: black/orange-orange/red-black-white/blue-white/green. 5wires
Right side plug going into block:
brown-orange/black-orange-brown/white. 4wires
Does anyone know which of these wires are the ones to test?
Thanks, Lee

 

[rhealy]

was this ever fixed? I'm having the same problem with my 2004 johnson 90 HP. the engine will start but has a miss at both full speed and ideal. what i have done already:
*new coils
*Power pack
*carbs completely rebuilt
*plugs
- what i haven't done is, Optical sensor, Stator.

so the motor will always start and run with a miss. it has the quickstart and that is working but i did not disconnect the temp sensor wire(s) i believe that is the Brownish wire with white strip and it has one on both sides of the engine between the cylinders.

so a question is has the optical sensor been an issue with this engine acting like above. has the stator been an issue or show the signs above?

 

[racerone]

Start a new topic on this motor.