Ok I took the turndown off and that baby sounds loud as hell I like it I want it to sound like that but i dont want to leave the turn down off because i will be going thru mud I took the screen off and it has improved a little in sound i seen on google in pics a guy had drilled holes inside i dont know if thats a good idea or not anyone can help  

noo!!!

don't drill holes in the factory exhaust on a 4 cycle engine.

here's the reason...

if you ride it cold then when you turn the engine off cold air can get in to the valves.  and if you get cold air on an extremely hot valve they tend to bend.

do you normally take the atv through mudholes that are deep enough to cover the exhaust with water?

if so then you need to route the exhaust differently so that it's higher.

even with the baffle in, if you run it in water deep enough and the engine dies then water will backflow into the exhaust and to the valves and warp them, not to mention allow water to get into the cylinder which could cause the piston to fail.

alot of the mud riders who drag them through extremely deep creeks run their exhaust straight up from the cylinder like you'd see on a farm tractor.  

i take it thru mud but not where i float it where the exhaust goes under can i run it without the turndown  

as long as you are not getting the muffler under the water you should be fine with a 4 cycle engine.  

ok cool im going to do a little riding tomorrow thanks man  

i have a honda Trx250ex i havent added anything to it.. all stock parts still on it. would removing the baffle cap harm my engine over time?  

it shouldn't hurt it, as long as you don't allow water to enter the exhaust or anything to clog itr.
but you may need to readjust your air/fuel mixture on the screw to make up for the extra exhaust flow.  

i loves the sound an un-baffled 4 strokes they sound so awesome and its free