mhr-roxs

Hi there new to web site ill try and put all the info in one post I have yamaha aerox all tuned up really nice bike apart from one thing it has alot of back pressure in the water but it was fine when itwas 1st done witch was 2 and half years ago I think but put it away for winter and then last summer I got it out and now have this problem its ok on tick over but when I ride the bike up the road and back there is water all over my mud guard and I take my front panel off and the top of the water bottel and rad is wet but no leaks in rad or water bottle my dad said the lid to the water bottle will release a little bit if there is to much pressure but its confusing because it does it until all the water is out the water bottle please help any ideas and sorry for some mistakes on touch screen phone I know yous will understand