Ok they quad has been cutting out and running irratic for a while now. The jetting was spot on before and ran with no problems what soever and since it runs fine and cuts out not bogs or runs crappy i am figuring its electrical.
the coil measurements are
primary .04 ohms with the specs being .08-.10
secondary is 5.58 with specs being 4.56-6.84

stator measures 1.8 with specs .288-.432

So given that i am thinking bout replacing stator and voltage regulator recitfier and get a new coil. But it was cutting out before and i changed the coil mainly because the bottom spring broke. and i also replaced the stator thinking it was the problem and neither cleared it up. I do have a gutted harness to sidewinders diagram with only lights and fan. I only run with lights on very rare occasions. All joints are soldered and shrink wrapped. and i have a 4700 capacitor in place but my friend noticed today it was for 35volts. Will that make any difference at all? I wouldnt think it would going off that the current doesnt have to go threw it to get to the coil. Is there any possibility it could be the flywheel? dont know if i have ever read of one going bad but not sure. If someone has a good stator out of the quad would be nice to have the ohms on it to see if the one i replaced is really bad. I am willing to all suggestions just really want to get it cleared up before i tear into it to gusset frame and such. i have swapped in a known good cdi and voltage regulator and neither helped. Just about 99% sure im going to replace the stator and coil and voltage regulator unless someone can tell me otherwise.

anyone tried a trail tech stator and regulator kit? just thinking bout going with that because i definately want a new voltage regulator and stator just think usually with a coil it works or it doesn't but waiting for someone who knows more than me to chime in

anyone got any input? even to tell me the stator is bad lol

If your sure you don't have any loose wires, and the flywheel is tight, and the key is good, then Yes........ It's probably the stator.

im sure i dont have any loose wires i just pulled the harness apart and checked it all out and everything is good. i will check the flywheel but checked it not 2 long ago so hopefully that good i will check the key though. just curious if thats a common thing on the yfzs? i havent read much about people sheering them.

It's not common, but I have heard of it happening.

I did have one YFZ that the stator and CDI went out at the same time. Everything checked out within specs. We changed the CDI...... No spark. We changed the stator........ no spark....... So what the hell, we changed both at the same time and vola...... Spark.

Sounds like a bad ground to me if you have a gutted harness. That seems to be the biggest issue, hardest thing to maintain is a good ground with a gutted harness.

ill double check the ground i have it grounded to the top engine mount that bolts to engine so i wouldn't think that would be a problem but will run a jumper wire tomorrow if it rains. but while im at it going to pull flywheel and check key and make sure its not sheered and while i have it off starter clutch will get tossed. after that ill try the ground. i have spark and it runs just runs like crap 1/2 and above sometimes so don't think its a problem like daddio said but always an option.

been working 2 jobs so haven't had a whole lot of time to mess with it like i want to but long as it rains tommorrow i will get on it.

nerd i assume you had some sort of ground issue before? where is another good place to ground it? other than motor mount.

flywheel key is fine and nut was tight but found something interesting

i checked the flywheel to cylinder and case resistance just to see what it was and before i pull the flywheel it was 35 ohms well i thought that was a little high but not sure what it should be. so i took it off and pulled the starter clutch and gear and after i put it back together i got 1.2 ohms so not sure if that was the problem and dont know how i changed it but just interesting.

well i took it to the badlands today to try it out and ran ok for a bit then started running like crap so i checked the plug and it was little white so i uped the main from a 160 to a 168 helped out a little for a bit then started cutting out mid to top again so i unhooked the fan thinking it might help and bam ran great for a little bit then died and wouldnt start havent checked for spark yet but guessing stator and regulator need replaced like stated above just wanted to check to make sure the grounding issue with the flywheel didnt resolve anything. i also checked and im gettting plenty of fuel to the carb and float is all set correctly so might try like daddio said and do cdi 2 if stator and regulator dont fix problem. If anyone else has any ideas im open to all suggestions i really want to get it figured out before i tear it down to gusset the frame

Finally think i got it fixed!! got a trail tech stator and voltage regulator and put on and seems to be running great didnt ride it much yesterday but enough to get it warmed up and make sure it wasnt sputtering. seems spot on with the 168 now 2. now just got to tear it down and gusset frame and hopefully get it powder coated!!