Nak, that much difference in a pilot jet would explain all the issues you are having. Perhaps the guy was trying to solve an overheating issue?
On the XR, going as rich as possible makes a huge difference in engine temps. But there is a limit of course. It also compensated for the absence of an accelerator pump to a small degree. But the real solution - for me - was putting an Edelbrock Quicksilver on it with an accelerator pump, bigger aftermarket radiators, hotter thermostat (counter-intuitive ain't it?), Redline Water Wetter, and a manual switched KTM fan for slow going. Complete solution. NEVER boils now, never floods, 1-3 kick starting even after dumping.
I got tired of people saying "just ride faster". Some of the places I like to ride, there just AIN'T no faster, and I don't want to boil over. Ride as fast or slow as suits you. It is all about your enjoyment, not measuring up to someone else's standards.
Some of those ideas may serve you well should you find yourself in a similar pickle. It is solvable.
Heb Dduw, heb ddim; Duw a digon
I'm that gun-totin', farm-raised, evangelical, pro-environment, OHV ridin'/drivin', Southern civil rights pro-labor Liberal yo' momma told you couldn't possibly exist.