Hello, I need a little insight on my 770. My son was using it and he ran it out of fuel. Now, I can't get it to start. I have tested by squirting a little ether but it only runs until ether is burnt out. I need to know where to start bleeding my system due to it likely has air in it. I have went ahead and check fuel flow from tank. I get a good strong flow from tank to first filter. Then the only way I can fuel past the first filter is loosening the 7/8 nut with a spring on it between the filters. When it is in tight fuel won't flow but with it loose it will start flowing but not much more than trickle. I am afraid to take it all the way out because I don't want to lose the little spring (after seeing what was on it). Is it possible that it pulled something from bottom tank and plugged it. I am planning on putting new filters on it to make sure they are okay. Any help would be appreciated. Forgive me for this being such a long post.