I switched from a 240 main to a 290. Runs good but when shut off makes gurgling noise?

[Jon P]

I have an 03 Yamaha blaster. Has fmf exhaust and airbox lid is off. Supposedly it has a big bore kit. I switched from a 240 main jet to a 290 main. Seems to run good but makes gurgling noise when I shut off? Any answers to why? Thanks

 

[Larry's Shee]

Try taking the gas cap off, the vent may be plugged