You cant leave something sitting so long and expect it to start and run normally. Ill tell you this,ever since they took the MTBE out of the gasoline about 3 yrs ago,and added 10% ethanol,the gasolines shelf life has been cut by over 50% from what im seeing.Stabil isnt enough anymore,you need to use the fuel,and put new in or drain it fully,and drain the float bowl,and put fresh fuel in when you need it.
At my home,I have a 10K Northstar generator,it has a sweet running V twin Briggs Vanguard engine,its never failed to start for me,but i run it at least 1/2 hr every 2-3 months when im not using it.I add stabil,and keep the tank full(10 gallons),and if i dont use it,every 3 months,I drain it thru the fuel hose,(it pops off in a few seconds at the filter,)into 2 -5 gallon jugs,and use it in my lawnmower,or snowmobiles.I then refill the generator with fresh fuel,start and run it 5 minutes,and im set for another 3+ months easily.You have to make time for this,it only take 15 minutes every few months,and you will be rewarded with a good running generator that works when you need it too.Also chaneg the oil and filter every yr,whether you use it or not,run it 15 minutes first drop oil and filter.Its money well spent.
At work I have a 10K onan/hobart welder I sue for backup power,same proceedure,also for my dads house a smalle 4400 watt Chicago pneumatic long run 8hp Honda,it runs perfect as we run the fuel thr it as well.
I would keep a can of starting fluid if you have a tempermental engine,with a dry float bowl,a shot of ether will get it lit and running sometimes when you just cant get gas to it fast enough.
