Mercury Sport Jet 90 no spark

[TPyles]

I have a sport jet 90 S/N 0E043715 in a small Baja jet boat.The motor is a 3 cyl. 3 carb model. It was always a hard start when cold but the more it was used it seemed to improve. It has a new battery and zero spark. I have checked all connections and the plug wires and replaced the plugs. Still no spark. Could someone please suggest where to start and how to test each section? I have a multi meter for ohms and voltage if one is needed. I need to know how to trouble shoot and diagnose my problem. Thanks for any advice.

 

[funpilot]

Re: Mercury Sport Jet 90 no spark

Hey TPyles, welcome to iBoats!<br /><br />Does your motor turn over? My Sport Jet 120 wouldn't. The tracing procedure is in the manual by Clymer, I would imagine the Seloc manual has the same procedure... basically you need to buy one.<br /><br />But, trace the battery voltage from each component to ground, starting at the battery... through the solenoid, up to the 20 amp fuse down to the main engine harness to the key and neutral lock out switches. My problem was a bad amp connector in the hull between the connector before the key switch and the connector at the engine.<br /><br />By the way, if you take your ignition switch out... mark and note the wiring very carefully. I ASSumed that the wiring would match my manual... but it didn't. That was an extra hour of trouble shooting right there!<br /><br />If it turns over, you really need to check out Kenimpzoom's posts. His link will take you to a really good ignition trouble shooting guide on his web site. Just click on his signature and go to his homepage.<br /><br />Good luck