[2 Bit Hook'R]

I have a 300 and have had similar issues, but they have always been fuel related.
water seperator filter, then engine filter, then there is a filter that only a yamaha dealer can replace, it is a vapor filter (vst or vsx) ? they will know what your asking about! also have you been burning straight gas or are you burning gas with ethynol? they say you must shock your existing fuel during your 1st 3 fill ups. here in N.C. it just started showing up at the docks. they say you should not use one then the other! has something to do with water break down in your tank. just a few thoughts! Jim