2005 Yamaha Bruin 350 throttle up it dies

[docdave2003]

2005 Yamaha 350 bruin    ATV sat for two years...hard start so drained the gas tank...new gas...started hard even with choke...but  once started would go through the country side...sat for a month...hard start so pulled tank and cleaned it out...starts easy and idles fine without the choke...but the minute i try and throttle up it dies...if i start it with the throttle held half open will start and run...goes back to an idle just fine...but dies if i throttle up at all...looking in the ventura of the carb it looks like there is something restricting 2/3 of the air intake...? possible ruptured diaphram?...time for a new carb?   

[Mech]

If the diaphram goes, it normally doesn't rip right to pieces and get through the small holes in the slide. Best fish whatever it is in there out though. Pull the slide and you can see down from the top. If it's not that blockage causing the problem then it sounds like a dirty carb or needle's come loose in the slide. First thing is pull the slide and check the blockage and needle(easy), then use the drain screw to check there's plenty of fuel getting through(easy), then pull the carby off and clean it(pretty simple). You could try a new plug first(cheap).

[docdave2003]

thanks for the reply...old gas and varnished up...went ahead and replaced the carb and runs great...doc

[Mech]

Well done..