1989 90hp Mercury no spark

[Fishing in driveway]

Just rebuilt all three carbs and now I have no spark. 2 carbs were leaking fuel and I was having acceleration issues, but once it was going at WOT it ran fine, only when trying to plane it struggled to RPM. Now after pulling the carbs there's no spark any ideas

 

[alldodge]

Howdy

Have you checked the kill switch/lanyard?

 

[Fishing in driveway]

That's next on my list, I believe I remove the yellow/black wire to disable that switch as well as the Mercury switch. It's just funny how that happened after rebuilding the carbs

 

[alldodge]

Either that or a wire was disconnected/grounded when doing the carbs

 

[Texasmark]

The yellow black or black yellow wire (forget which....one is ignition kill and the other fuel enhancement solenoid activation...."choke") connecting to the ign switch at the OFF position sends ground to the 3 CDI's and kills triggers when you want to stop the engine. If it is grounded any other time there will be NO SPARK. If you did your carbs and still have fuel leaking out the venturi, either you didn't set your float correctly or your needle valve/float linkage is binding inside the carb.

 

[tommarvin]

If all wires are back in place and nothing is grounded out. I would get a Lisle 50850 spark checker set it to 3/8 inch gap and see if you have spark on any plugs.

CDI electronics.com has a very clear trouble shooting process, put in your year, make, HP, start with coils, scroll down for trouble shooting coils,swap a good coil for a bad coil for example, to test a bad coil then power packs, trigger, stator .
Free outboard service manuals at www boatinfo.no/lib/library.html click Mercury on left, find your motor, find what you need and fix it. Carbs aren't easy to rebuild.

 

[Fishing in driveway]

All right guys I found a ground wire that had been in the process of melting on one of the coils thanks for all of the advice

 

[Fishing in driveway]

Alright fellas I took the boat out on Monday runs wonderful however it takes about ten seconds to plane out I was thinking this was due to the prop size, the individual I bought the boat from stated he installed a torque prop I was thinking this was related to the planing issue, it doesn't bog down just takes a bit to plane

 

[Fishing in driveway]

Prop size appear to be 19

 

[tommarvin]

Good for you, we have fins bolted to the cavitation plate, I think that's what its called, they help to plane.

 

[Fishing in driveway]

That's a good idea I will try that