I have heard stuff about cleaning out the welds on the stock 400ex headpipe. How do you do it? I bought mine with a slip-on on it. Im gonna get a full system as soon as possible but i wanna see how this works. Thanks, Anthony
Pro Rider
Take the headpipe off of the quad ad look inside the 2 opening that go onto the head. About 1/2 inside you will see the welds that we are talking about. They are only on the 400stock pipe. Take a Dremial tool or a drill with a stone wheel and grind out the welds so that they are flush with the side of the pipe. This will make the air flow better inside the pipe. You will find that you will not need an aftermakert headpipe after this. By cutting out the welds this will addabout 1/2 to 3/4 hp. Getting the pipe off is the hardest. cleaning up the welds should only take about 15 min. Most of the aftermarket headpipes are the same size as the stock headpipe. All of the gains are in the slip-on.
Pro Rider
i will add this if cleaning the welds make sure you wash any metal shavings out of the head pipe before install so you dont suck any shavings into your cylinder.
Thanks, Im gonna do that as soon as I get the chance. I need to go pick up a stone wheel for my drill. I dont have a dremel. I've been thinkin about gettin one of those. Thanks again, Anthony