After about a year of my airplanes hanging on the wall I decided to go fly today. Took both planes into the garage to make sure they start before going to the field to fly. And I had the hardest time starting either. The first, O.S. 10 took at least 30min to get it to make any noise, it started and ran for about 10sec then died and it wont start again. Im sure my glow plug ignitor is fully charged (I used 2 different ones). Mabey the gas is bad? Its about 4 months old. Any help would be much appriciated. And still after a day of trying to get both planes running niether one wants to start, they dont even pop or make any noise.

Could be congealed castor pluging the fuel lines up. Are you sure it is getting fuel?

Prime the carbs with a little squirt of fuel, and they should at least fire up.
If you have some carb/choke cleaner around the garage....pull the needle
valves out, and give it a squirt into the nozzle of the carb. If you have some
compressed air, give the nozzle a blast or two. Reset the needle valves at
about two turns out for a new start.

The carbs and fuel systems must be clean, and the fuel must be good, if you
want to get them running. Put new glow plugs in as well, if you have some.

FBD.

if ypur engines seated for 3 years without after run oil and such procedures, it's hard to get them started. I think fbdave told right, put little amnount of fuel irectly in carb and try then. check fuel lines

Mr Bakurin,I dont agree with you, My OS max .25 got started immediately after 24 years nonstop resting,just after a good priming.
So I recommend to prime it by carb throat manually and test.If runs, it shows problem is on fuel feeding.

it means u agree only with my 1 opinion gospodin turk
if bearings are rusted it needs some antifreeze procedures, wjich i don't know. it can free up gummed bearings

Take out the plug and check it for glow. If you have glow it is either starved, flooded or the starter is drawing power from the glow igniter. How are you flipping the engine?