GN250 Scraping noise at idle after stator swap -Troubleshoot

[bikebusy]

Hi everyone,

I’m chasing a repetitive, mechanical scraping sound on my Suzuki GN250. The bike is silent when I hand-crank the engine with the spark plug out, but the noise returns once it’s running.

What I’ve done/checked so far:

Stator: New unit installed. Continuity is good between all three yellow pins; no shorts to ground.

Flywheel: Cleaned inside and out; no metal debris or "witness marks" found on the magnets or rotor.

Gasket: Tried both 0.8mm and no gasket (dry fit). Hand-cranking was silent without a gasket, but the 0.8mm version didn't stop the noise at idle. the bike came with a much thinner gasket (paper like) but considering the replacement kit came with a thick gasket, I thought that was the way to go. I can't seem to find definitive information on gasket thickness.

Clearance: Pickup coil and internal wiring look clear with no obvious scuffing. Stator bolts are tight (Loctited).

Oil: Fresh oil and filter are clean—no new metal shavings.

Starter Gears: The noise sounds loudest through a stethoscope at the center inspection cap. The idler gear is meshed with the starter clutch gear.

I've been using Gemini AI to troubleshoot the issue (which I acknowledge is not ideal) and it states that there could be a washer missing from the idle gear. However when I check the blowout diagram there is no washer present.

https://www.suzukipartshouse.com/oemparts/a/suz/50d3ed40f8700230d8b4b2df/starter-clutch

what I'm trying next is making a paper gasket to see if the difference in clearance will have an effect. if that doesn't solve it, I'll have to check her in with a mechanic as I'm at my wits end.


Thanks for any leads.
____________________
Suzuki GN250 2005