That makes sense, thank you guys! Anyone know a good source for new main jets. For some reason it has a size 70 in it, so it falls on its face at half throttle or above. I’ve seen some individual oem jets on eBay, however maybe there’s a website that sells kits? 

They need some type of a oneway valve on the end of the hose to let air in but not fuel out if the bike falls over.

post#11 sounds like the exhaust is blocking up. Classic symptoms.

Found my local Yamaha dealer was the best resource for jets AND the least expensive. $4.45/ea. Not sure which main jet style that carb uses though.

Good point!