Et300 no spark

H

Hammer Down

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Apr 13, 2013
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Flint
I'm trying to figure out the no spark issue with my sons ET300. I'd guess it's a 79-80. I tried a new coil but that didn't work. I'm guessing the stator? I've never had to do more than clean carbs on my enticers for years so I don't even know where to start. Do the tethers and ignition/kill switches ever go out? There are orange and grey wires going to the tether and kill switch. Would the two wires be spliced together or not, in the run position.? Thanks for the help.
 

A normally open system so splicing them together would kill ignition. Unplugging the ignition, tether or kill switch takes them out of the system. If they are all unplugged you should have spark.


To test switches on most Yamaha's just unplug one at a time and retest for spark. No change switch ok. Change switch bad.

opsled
 
Ok. I unplugged both grey/orange connectors and no spark. How do I test the ignition switch? Thanks. Never mind, I reread opsleds post. I'll locate the ignition switch and unplug it and try again. Although, I doubt it's the switch. It died while idling.
 
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Check ground wire on ignition coil too. Engine air shroud is plastic. Coil is mounted to it. Have seen issues with ground wire here on occasion.

opsled
 
I have had similar problems with my ET300 as well, intermittent spark. It would/could start, idle and run then load up until it would just quit... check for spark - nothing. Leave it alone to cool off and the plugs would fire again. FRUSTRATING! Found the trigger coil would fail once it became heat soaked. Swapped ignition and all is well again! Also check for rust buildup on magnets.
 
I'll check the ground. Would a very dim headlight on occasion point to a bad stator? I noticed it doing that last winter
 
Does anyone have the torque spec for the flywheel? I pulled it and the magnets are rusty.
 
that could be part of dim headlamp.

clean the magnets while you are in there as i have heard that it can cause problems.
 
Great idea. I was thinking they would just rust over quickly after sanding but wasn't sure if a coating would screw it up. BTW , sanding those parts down did not work. I think I found a stator for it.
 
I've dusted them lightly w/ paint too. Heat seems to "loosen" the adheared paint over time. I prefer the ultra thin battery terminal protector. Warm up the metal before spraying it down.
 
I figure I should do the mag crank seal while I have the stator out. Is installing it the same deal as a crank or cam seal on a car? I did them on my Chevy metro which is basically a snowmobile engine. Or should I just leave it alone. I don't want to open up another can of worms. Any tips on installing/removing the seal?
 
last ones i got into i had to split the bottom end witch was a good thing as one of the crank bearings was bad on the 78 et340 i did.
 
So I got a 'new' used stator but when I installed the flywheel I could here it grinding on the new stator. I pulled the flywheel back off and it definitely is grinding. Where do I go from here?
 
is it the same size as the one you took out? i have seen the pick up coil adjusted out too far on a few out boards, when they are adjustable.
 
It looks identical. I'm thinking maybe a chunk of dirt or rust may have got in there. I'll retry tomorrow.
 
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