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Post originale di: John Painter ,


This is the rule of thumb diagnostic four any small engine, two stroke or four stroke - you need spark, compression and fuel.  [br]


Remove plugs,  ground them on an engine bolt and pull the starter to check for spark.  If there’s spark they’re not the issue.  If there’s no spark replace them and test again, if there’s still no spark you probably have failing coils. The coils can be tested with voltmeter, you can look up online how to do that and voltage for your engine, it’s not hard to do.

If there is good spark, remove the plugs and put your finger in each hole on the engine to plug the hole, and pull the starter.  If there’s a strong puff of air pushing your finger in each cylinder you have compression.  If you feel nothing pushing against your finger you’ve got no/weak compression and need to rebuild and replace rings if it’s a two stroke.  If it’s a four stroke engine it may have stuck valves or timing chain skipped a link or two. Either way you’ll need to open up the engine if you have low/no compression.

If there’s spark and compression you’re not getting fuel, and you should clean your carb and probably replace fuel pump.

Outboards I’ve had that behave like yours 80% of the time it’s been the carb and or fuel pump.  Usually the fuel pumps are not very expensive so I just replace them with new OEM pump, then take the carb apart and clean it well.  Plenty of vids on YouTube how to clean a carb.

I think you’ve got a common issue and pretty easy to fix yourself and know what to do in the future.  Good luck!