[Dunny1]

I have a 2006 Vinson 500 manual that has started making a humming/whistle noise that sounds like its coming from the top of the engine(not sure though). There is no smoke or oil burning and it rides and drives fine. The sounds is worse when it’s cold outside but after you drive it for awhile it goes always. Trying to figure out what the problem is and I guess it won’t let me post a video of the wheeler running. So if you have any ideas any help would be greatly appreciated.

 

[Rdc]

Welcome to the forum. If it stops after it warms up it’s something like a crack that seals up after the heat makes the piece expand like maybe something rubber. What about a crack in the intake boot between the carb and cylinder.?