P220g - spark on tester but not on plugs

[TC10284 119]

520H 4120oe02 1032657 with p220g. 

 

Earlier this year in spring, I mowed with this tractor. It suddenly would start sputtering and die after 20 or 30min unless I did full choke. It would run again for a bit after cooling down and do the same behavior. Replaced fuel, cleaned carb. Same behavior...

 

OK, so that told me there was a possible issue with the ignition control module. So I swapped it. Swapped the rotor also. 

I can get spark with a spark tester, but I see NOTHING on the spark plug (ngk tr5). I just tried a totally new ngk tr5 plug and still get the same results. Spark in the tester but not on the plug. I've tried jumping from battery positive to coil Positive. Same results. I dump some gas in the carb and I get nothing. No backfire, not a puff, not even trying to fire. 

 

Battery is good. I've even tried a booster on it. Flywheel Magnets are not stuck to the stator. New coil. New condensor. Compression on both cylinders good. Even replaced the ignition switch. 

 

I am currently at a loss. 

Edited 3 hours ago by TC10284

[pfrederi 21,089]

What kind of spark tester are you using.  The Harbor freight neon bulb type will often flash yet there is insufficient juice to fire the plug.  B&S type will give a better picture of strength.

 

 

[TC10284 119]

The harbor freight kind, yes. 

 

Also, sometimes I see an initial Spark on the plug when I turn key to Start and then nothing, and then one when I go from Start to run, or sometimes run to off. 

Edited 3 hours ago by TC10284

[Wild Bill 633 937]

1 hour ago, TC10284 said:

The harbor freight kind, yes.

FYI, the Chinese always give you more than you expect. Like their carbs come with extra machining chips and they need to be deburred. Maybe they added spark to their spark tester.

Edited 1 hour ago by Wild Bill 633