1985 evinrude 150hp xp blowing main fuse

i have a 1985 evinrude 150 xp e150stlcos that keeps blowing the main fuse that comes off the starter selnoid. it only does it when it is in the water and you get it up on plane. what are some probable causes of this? comments please

Re: 1985 evinrude 150 xp blowing main fuse

Check all associated/related wiring..... loose connections, tight but dirty connections.

Possible short within control box. To test theory (engine not running) but key in ON position, spin prop and put engine in forward gear, in normal fashion advance the throttle lever up to the full throttle position. If the fuse blows, the problem in with the control box.

Re: 1985 evinrude 150 xp blowing main fuse

Joe thanks for your response to my problem. however i have tried this procedure and it does not dissclose the problem. the problem can will only happen with the boat on the water running while trying to get it up on plan. i have unkooked the wires to battery that operate lights and gauges and unkooled the trim while running it on the water and it still blows the main fuse. ive noticed a miss in the engine when it blows the fuse and after it blows the fuse the motor smooths out and runs fine and when i turn the motor off i have to put another fuse in to get it started again. it then starts right up and runs till i try to get it up on plane again.

Re: 1985 evinrude 150 xp blowing main fuse

joe reevs i thank you for your respnse however i have tried this procedure which does'nt disclose the problem the problem only occurs when the boat is in water while tring to obtain plane. have unkooked wires to lights and guages and have unkooked trim trying to trouble shot but however still blows fuses. have noticed a miss when it happens and after it blows fuse boat runs fine. when you turn the motor off you have to replace the fuse agan and after doint this motor starts right up and runs till you try to obtain plane again.