I just bought a 1994 yamaha wave raider 700. The guy I bought it from said it has sat for about a year on a full tank of gas. I took it out to test it and noticed that its kind of boggy if you go full throttle out of the start it will just barely go but if you let off alot and feather the accelerator it seems to go how its suppose to. I changed the plugs in it. I kinda think that maybe it is the bad gas in it. Please help me.