Purchased a 2007 Hawkeye 300 4x4 recently.

1st test drive went pretty good. Ran very well but would stall out if it idled more than a minute.

2nd time out wouldn’t start. Checked oil, gas in oil. **I did not shut off fuel from tank and it was in back of my truck a week. So I take the blame for that instance.

Changed oil, it started right up. Idle issue stills exists.
So I decided to pull the carb. I was expecting a carb with pilot adjustment. No external adjustments on this BST 34 Mikuni carb.

Opened carb no gunk in the bowl. Needle/Seat looks new. Pulled pilot jet- verified correct size. Clean and not obstructed. Inspected top of carb, diaphragm and needle clean, nothing looked plugged or gummed.

Carb to airbox boot needs to be replaced. New one arrives Weds. I sprayed starting fluid looking for leaks in boot- none found.

Test drive after assembly in driveway- a lag or stutter when you press throttle. Clears at 1/4 throttle. No issues WOT.

Took it to hunt club this afternoon- got videos of laggy throttle response. Rode an hour maybe 3-4 miles trail, mud, woods. Back at truck, very hard to start. Dies immediately with any throttle. Sometimes it would start and idle- die with throttle

I think it’s pilot circuit of carb. With no adjustment screw, where do I look next?