Tried everything, except what's really wrong.

[Panhandle Nick]

NSF 15C, 2010 MODEL, won't start.
Replace magneto, pulser coil, ignition coil cleaned carburetor twice, installed new plugs tested kill switch and neutral switch. This thing won't start. I've also tested peak voltage, but that's irrelevant because I've replaced all the parts. The CDI i think it's called is all that's left to buy. Can anyone help.

 

[Scott Danforth]

What diagnostic steps have you done, or have you just thrown parts at it?

 

[Panhandle Nick]

I tested spark plugs, thought they were weak. Replaced after setting gap.
Use multi meter with peak voltage adapter. Seem to indicate magneto was bad so I replaced that. Tested kill switch and it was fine tested neutral safety switch and it was fine. After following tests from the tehach to site it said most likely ignition coil was bad so I replaced that. Before all this I suspected bad fuel or clogged up carburetor so I cleaned the carburetor and it looked really good I cleaned it a second time just to make sure I hadn't put anything together wrong.

 

[racerone]

What motor ?-----Does spark jump a gap of at least 5/16" ( 8 mm ) on a test device ?

 

[Scott Danforth]

Start with basics.

What is the compression?
Can the spark jump the 8mm gap as indicated above?
Has the flywheel key sheared?
If all above is good, only thing left is fuel system (carb, fuel pump, etc)

 

[Panhandle Nick]

What motor ?-----Does spark jump a gap of at least 5/16" ( 8 mm ) on a test device ?

Motor is 15 hp Nissan Marine 2009. Electric start.

 

[pvanv]

Did this just happen, or have there been issues for a while? You replaced the alternator? Never saw one fail. What is the voltage out of the alternator going into the CD? Did you test the CD? What method did you use to clean the carburetor? Do you now have spark?

 

[Panhandle Nick]

Did this just happen, or have there been issues for a while? You replaced the alternator? Never saw one fail. What is the voltage out of the alternator going into the CD? Did you test the CD? What method did you use to clean the carburetor? Do you now have spark?

I have no history with the engine, it's new to me. As for the carb, disassembled cleaned with carb cleaner, low pressure air to ports etc. I did not yet the CD. How can i do that. But there's a good spark jumping 8mm. Should that tell me that I have everything fine on the electrical ignition end?

 

[racerone]

If spark jumps an 8 mm gap it would rule out ignition issues

 

[Scott Danforth]

You have spark..... Now look at compression and if the flywheel and ither items

 

[Sea Rider]

Is the ground terminal of each electrical component included where it screws at the crankcase impeccably shinny clean?

To check if the fuel ignites properly : Remove both spark plugs, squirt a small dose of fuel indide each combustion chamber, put plugs back in, prime the fuel bulb till fully firm, start the motor as usual, if starts to run excellent, if not likely a fuel related issue ?

Happy Boating​

 

[pvanv]

You need to properly clean the carb. Just spraying acetone type generic cleaner is not adequate.

 

[Sea Rider]

The spark on those motors should jump a healthy 11mm not just 8mm, test again and depending on condition check if the fuel squirted on both cylinders as noted in post 11 ignites well when the motor is started.

Electrical components can go bad over time, the ones having erratic behaviours when working at load are the hardest to diagnose properly. Parts swapping it's the fastest way to troubleshoot well if having all of them to try one at a time till the culprit is found, that's an expensive troubleshooting that will put the combo right back on the water. If found it's not a fue/carb related issue install a new CDI which it's the only electrical component left to try...

Happy Boatng​