Carb, bad gas, or a mix of both?

Bike:

2000 Yamaha yz426f

Stock exhaust, stock air filter.

I took it on its maiden voyage Saturday after plating and I know it kinda sputters at cruise/part throttle sometimes. Didn't think much of it but when I was on my way home from this short ride, it came to a sputtering/backfiring stop like it ran out of gas. I was riding up an incline and it had plenty of fuel in it. I tried numerous times to try and kick start it again after the incident and it would randomly start for like 5 seconds then backfire and then die and not start again. Towed it home and now it starts up just fine on the stand. Maybe I'm to short but I leaned it up against a crosswalk light and it still wouldn't start. (I don't normally have to do this but I thought that maybe I wasn't kicking hard enough)

Maybe a carb cleaning and new gas? This gas has been in it since winter. It idles fine, but I know when I try to go from a little bit of throttle to WOT or close to it would hesitate then kind of sputter then kick in like vtec or something.

What do you guys think?

Bike:

2000 Yamaha yz426f

Stock exhaust, stock air filter.

I took it on its maiden voyage Saturday after plating and I know it kinda sputters at cruise/part throttle sometimes. Didn't think much of it but when I was on my way home from this short ride, it came to a sputtering/backfiring stop like it ran out of gas. I was riding up an incline and it had plenty of fuel in it. I tried numerous times to try and kick start it again after the incident and it would randomly start for like 5 seconds then backfire and then die and not start again. Towed it home and now it starts up just fine on the stand. Maybe I'm to short but I leaned it up against a crosswalk light and it still wouldn't start. (I don't normally have to do this but I thought that maybe I wasn't kicking hard enough)

Maybe a carb cleaning and new gas? This gas has been in it since winter. It idles fine, but I know when I try to go from a little bit of throttle to WOT or close to it would hesitate then kind of sputter then kick in like vtec or something.

What do you guys think?

could try cleaning the carb and installing new fuel but it sounds kind of like a bad coil if it only does it after it warms up then starts up fine after cooling down.

Makes sense. Is there a way to test the coil via the manual?

Found the tests in the manual. I'll check that and report back.

Thanks for the tip!

Just tested my coil. Resistance should be .20 - .30; it's reading .14

Tested the secondary coil, got no resistance at all.

I think I found the culprit.

Checking the CDI now.

10-4, no problem.....I know the dealer tested mine and got some weird numbers that made it seem ok but was off a tad...glad you found the problem

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