Sounds like dirt stuck in float valve, preventing it from shutting off. Pull float bowl off offending carb, take float out, unscrew float valve and clean it out. Re-install and test.
did all 8 jets but sucking air in rubber on bowl side cant find any carb kits for 250. 400 and 600 every where are they the same size bowls
My first suggestion is to be a little more specific about the problem Theres 4 carbs and alot of places fuel could be leaking from. Sounds like its time for the inevitable carby overhaul As simidau suggests , Litetek have a complete kit for the whole carby <!-- m --><a class="postlink" href="http://litetek.co/ReplacementPartsYamaha.html">http://litetek.co/ReplacementPartsYamaha.html</a><!-- m --> Strip them down and clean them out properly ..... look online or here on the correct procedure to do it the right way. Theres more than 8 jets for starters .... theres 12 just on the jet housings. And as Dave mentions , a float could be stuck open .... I found 2 granite boulders in 1 of mine. Have a look here and you will see a few of us (including me) are in the process right now. <!-- m --><a class="postlink" href="http://2fiftycc.com/index.php?forums/yamaha-250cc-in-line-4s.95/">http://2fiftycc.com/index.php?forums/ya ... ine-4s.95/</a><!-- m -->