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Johnson 90 HP 1985 J90TLCOS Electrical Doozy

Usually this is to ground through a neutral safety feature and/ or throttle position sensor, so accidents don't happen. In automotive solenoids it performs a different function. When and while cranking the engine is provided a full 12 volts to the spark coil to create a stronger spark. Then once the key is released to the run position it drops to zero volts and coil power is supplied by either a ballast resistor or a "resistor wire" which carries only about six volts to the spark coil in order to prolong breaker point life. Does your neutral safety switch work? Will it only spin over in neutral? I think on your motor, the safety features are incorporated inside the controls.
 
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Yeah neutral safety switch is good. Finally got aroubd to the lower unit and lo and behold I have the forbidden butterscotch milkshake. Going to pressure test and replace seals this afternoon
 
If the pressure test doesn't show an obvious leak, then vacuum test also. Both are advised, but vacuum tests came out in the last 20 years. Most mechanics were able to properly find leaks for the previous years with only inspection and sometimes pressure testing. Make sure when testing to drain all oil and move shafts while pressure is on.....this duplicates operating conditions. Many mechanics do not exercise the moving parts and have erroneous results.
 
I might add remember to never tow your boat while it is in neutral as the propeller seal or shaft seal's outer lip... Or outer seal if so equipped is lubricated and cooled by water.
 
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I planned to pressure test and spray problem areas with soapy water. By moving parts do you mean to move it between f and r? Also can you elaborate on the not towing in N? As in on thr trailer?
 
Right, you want to move the shifting component as well as input and outputs...... anything that moves when in operation that goes through a seal. Right, when towing on a trailer how often do you see the propeller turning? Lots of folks damage seals in this way....without knowing.
 
Just to finish this thread up I did test the lower unit, it held pressure according to factory specs. Also did impeller kit. Last time I took it out it went into SLOW mode. So after testing the stator I took a look at the thermostats but there were none! Just springs and a star wheel lookin thing. Why would the previous owner have done this? Its been converted from VRO btw. Considering my symptoms (shuddering/shaking and cutting power to about 2500 rpm usually accompanied by the horn) I am considering taking another look at the water deflectors as well. Ive learned much about this boat since I first joined this forum.
 
Crank the motor until the needle on the gauge stops rising. Since all cylinders are equal it's possible your gauge is not calibrated. You can check with an auto parts store as many offer free loaner tools.
 
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