I have an Xplorer 400, and it makes a pinging sound occasionally when wound all the way out.........at top speed and in neutral. Is it running lean or is something else causing this sound? Thanks.

 

I have a 00 Xplorer 400 and it made a sound like a valve rattle (I know I don't have valves, it just sounded the same as a valve rattle) when trailing , like if you were following someone and just maintaining the same speed with the throttle in one position. I talked with different people about it and most replys I got said it sounded like detonation and to move my needle clip. Tried that with little or no change. Then I ran some higher octane gas and it went away. I was running 87 and now I run 92. I never had it do it at full throttle and I've had it wide open enough that I would have noticed. I don't know if any of this helps but thats it.

 

She's lean on top end. What main jet are you running and is the bike stock?

 

What Gas octane you running if it is 87 maybe should run 92 in it they will ping with to low of an octane like cars do

 

I would say lean from Main Jet or Air Leak. Spray starting fluid arounf the head,base, intake boot, carb & air box boot & see if you engine revs up a little. If it does, air leak. My blaster had a cyl. base gasket leak and did the same thing until I blew it up. Once I pulled the cyl off and see the gasket, I knew what the sound was from the last ride. Good Luck and check it ASAP.

 

I vote for too low octane, I always run 92 or 93 and never have a problem.

 

Fasterthangas,

While the pinging was happening, here's how my bike was set up: My bike has a wiseco standard piston in it, oil injection removed, and I was running Mobil 1 synthetic 2-stroke oil at 40:1 with 87 octane gas. It has a UNI pod filter, and a Boyesen rad valve. Boyesen recommended a main jet change of 2-4 sizes smaller with their rad valve, so I had slowly migrated down to a 185 main jet. The pod filter is something I had just added, and I believe since it is so small in diameter, it may be more restrictive than the stock paper element. Yesterday, I drained the 87 octane premix with Mobil 1 synethic 2-stroke oil, and refilled with Maxima 927 premix at a ratio of 50:1 with 93 octane gas. I also removed the water diverter from the airbox lid to make the airbox less restrictive. I also did some trim work on the intake in the lid to let it breathe a little better. For 2001, Polaris completely changed the airbox design, and I believe that before my modifications to it that it was more restrictive. Specs say the bike comes stock with a 210 main jet. However, mine came with a 200. I've had a continuing problem of the bike loading up in mud holes while wide open. I was running a 190 main jet recently and the bike loaded up in shallow mud, so that's when I went to the 185. The bike had already made the pinging sound with the 190 main jet though. The vent lines from my carb are extended and run into the top of the steering stem. Since I did the air box mods, I will probably go back up to a 195 main jet and see how she runs. I need to tinker with the air screw. Used to, she would pull a wheelie in high range, but will only do it in low range now. I've pulled buddies with broken bikes back from rides 3 times, and my belt may be worn some, so I plan on replacing it......that may be the deal with the wheelies. Any additional recommendations will be greatly appreciated. Thanks.

Waylan

 

Have you adjusted the needle at all if you once you have it set for the top end power you can raise or lower the needle to help you mid range if it boggs or sputers in the mid an low range