What is the best pipe and clutch and any other mod that you can do to a 1999 400 explorer. I Am looking for more low to mid range power but don't want to hurt top end too much.

 

I would get the hot seat performance clutch kit. You get new springs, helix, and clutch weights. It will give you more low end power. I would also buy a delta v-force reed cage. You will notice a huge difference in the throttle response. A bigger carb will give you a lot more mid to top end power. You can gear it down buy buying a larger rear sprocket. Cut an extra hole in the top of your airbox in between the two holes. It'll give it more air flow and give you more power. Hpd exhuast is the best exhuast you can get. It adds 8-9 extra horses. It really makes a big difference. It's really loud though. If you do all this to your bike it will just scream. You should have a hard time keeping the front end down.

 

If it were me I would get a HPD clutch kit without the helix (about 89$) and get the roller clutch (replaces the helix) from HPD or Aaen (about 239$) to go with it. I have the Aaen roller and it gets rid of the lag in throttle response. The V-Force II reed valves are a great addition too. Pipe it and mod the air box for maximum power!

 

If all you want is some help in the low to midrange without spending a bundle and a lot of hassle: EPI clutch kit. I have one and it is great. Springs, weights, and helix.

Just thought I would give you another option...

 

Mean...that is one modded Xplorer! It must be amazing on the trails. How do you like the wheel spacers? Any problems?

 

It's an awesome mudder. In the trails it gets kinda tight sometimes. It's so wide that i have to make my own trails a lot of times. It does make it a little more stable with the spacers. Without the spacers the front tires would rub on the struts, so I had to get them. It's a blast to run it where it's completely wide open. It just keeps going. I would like to see other xplorers like mine. I think they are the baddest muddin and fastest utility quads out there.

 

I own a 93 350 4X4 that uses the same parts as your 400. Everything they say about a piped, clutched polaris flying down trails is true. Mine has the Hot Seat pipe and clutch kit, boysen rad valve (should have used v-force), shaved head, wiesco piston, self ported, 38mm mikuni carb (definetly recommend), k&n filter. These mods let my 575 pound polaris smoke my built 250x. My x will outrun 400ex and 400ex's can't touch my polaris on trails.

 

Hey guys thanks for all of the help I am going to look into some of those mods and see which ones I can work into the budget. Rick Ritter e mailed me and i will see what he can help me deside and whice way I want to go with this bad bike.