90 HP no spark

[zimnucks]

Ive got a 90HP yamy , Im not sure of the model as the tag is gone . Its a carb engine and Im not getting any spark , I tried hooking up the diagnostics but this engine doesnt seem to have a port for doing diagnostics . Any ideas of what to test ?

 

[zimnucks]

Ive just checked on Boats.net and it looks like this motor could be a 2003 model if that helps

 

[[email protected]]

Hook up a timing light to plug leads.Swing motor and check for spark.If no spark, hook up timing light to wires running from CDI to coils.If no spark, possible CDI problem.Check if killswitch is installed.

 

[zimnucks]

thanks for the tip , i changed the ign switch and that sorted out the spark .Now the engine backfires and when I got the engine all the coil and plug leads were off , I set them up according to a 90hp fuel inj motor and its still backfiring . Where could i get a wiring schematic or something to make sure its wired right . This motor was a mess when I got it .

 

[Zorfox]

Where could i get a wiring schematic or something to make sure its wired right . This motor was a mess when I got it .

Hope this helps.

 

[zimnucks]

thanks for the diagrams ,this is a 4cyl engine and only has 2 coils .

 

[hondamech]

Make sure the spark plug leads are on correctly. From the coil that has the #1 cylinder wire the other should go to #4 the others are #2 and #3. This ignition is called lost spark because they fire both leads each time.