Engine is "hunting"

[Keeperl]

My yt 6700  started to hunt then quit running. I suspected bad gas since I used some  gas that had been around for a month or more. Anyway , I pulled thes carb and found some gelatinous goo in the bottom of the bowl. I put in fresh gas after draining the old and I have removed, cleaned the carb several times.  Cleaned out the fuel lines from back to front. It runs now but mostly in the choke position and it hunts up and down. Meaning revs up then down any ideas????? Also I used aerosol carb cleaner and followed up with compressed air through all orifices after removing tubes jets etc..  Please ...any help!!!!

[YamaDog]

You could have an air leak between manifold and carb but it probably is gunk still in the carb. might try changing fuel filter and make sure the tank does not have gunk in there. starter fluid sprayed around the gasket will tell you if you have an air leak, do it while the engine is cool.

[rattosh51]

Add some gas additive like Seafoam to your tank also...