Hey guys,
I've got an Xplorer 400, and every time I get into a mud hole and have the throttle wide open, the bike starts spitting, sputtering, and smoking pretty bad. I'm thinking I'm a little rich on the main jet(it's a 200 right now, which is down one size from the factory), but I'm not sure enough about my diagnosis to go down to a smaller jet and risk engine damage. If held WOT in neutral until it revs out, it will spit and sputter a little, but won't load up. When it's in the mud hole, it loads up and acts like it is in reverse without the reverse override button pushed in. Any help is greatly appreciated. BTW, it has a boyesen rad valve on it, which requires a smaller main jet than stock.

Waylan

 

Walexa,
The best way I know to determine whether a bike is running rich or lean is to look at the plug. Of course if it is black, you are too rich, white too lean.
You may already know this, but if not, I hope it helps.

Greg

 

Is your plug getting wet ? try using dieelectric greese on it might help.

 

Hopefully this did not happen before you installed the reed kit? Or did it?

Sounds like you have lost your bottom end torque.

 

Greg,

The plug actually fouled out saturday in a mud hole. It was definitely black. I think I'm going to block off the oil injection and go to premix. After I do that, I'll check the plug again to see how it is.

Thor, I don't believe that I have lost the bottom end torque, as the bike will wheelie in low range, and has lots of snap off of idle. Thanks for the response, though.

As for before/after rad valve installation, I don't know. I just ran it around the yard every afternoon until the first tank of gas was gone to break it in. I didn't get to bury it in any mud holes during that first tank. Also, it never ever does this except when I run it into a mud hole, loading the engine under full throttle.

 

I own a 00 Xplorer 400 and I just had the same thing happen to me last weekend. My machine is all stock. I was going thru a really deep mud hole, as I got into it I was full open on the throttle and then it started to bog down and sputter like it was going to shut off. When I let up on the throttle it started to recover almost near idle. I got back on it and came on thru the hole and everything was working normal. I went thru the same hole two or three more times and it never happened again. It really blew my mind when it boged down like that because it has never even come close to losing power before. I rode the rest of the weekend and it perfomred like it should. I just kind of blew it off because it worked fine the rest of the weekend but now that I see your post I'm very interested to see what reply's come in.

USMC
00 Xplorer 400

 

When the bogging takes place, are you negotiating these mudholes in high or low range?

Is your air filter clean?

We are assuming that the smoking is injector smoke rather than belt smoke right?

You aren't hitting the water too fast initially are you? That could and does cause ignition misfire and belt smoke on occasion.

 

walexa, I've got the same mods, plus a few. Two things come to mind 1.If you are running the stock air filter you are almost certianly too rich on your main. Even with my Dynoport pipe and K&N, I can get away with a stock 210 main jet when the temps are above 70 deg's. I put on 75 miiles last Sat with temps in the mid seventies, the plug was a nice dark brown at the end of the day. 2. Polaris tends to error on the way too rich side of safe on there oil injection systems. Since your machine is new I'd have your dealer check out how rich your injection is set. Some dealers forget to check this during set up. BTW if your system is too rich by correcting this you will gain a considerable amount of top end speed.You should be burning about a quart of oil every 250 miles or so. I don't know about where you ride but here in Minn we do alot of running from town to town and it would a real pain trying pre mix a half tank of gas at a gas station! Just a thought. Just my 2 cents worth

 

If you cool the moter and head pipe very quickly such as putting under water.a 2 stroke will run rich untill the temp. starts to climb back up.

 

The time it happened to me I stopped prior to the mud hole shifted into low range and eased on in. I usually just try and go on thru just keeping good foward motion. I like crawling thru it nice and slow rather than trying to bust all the mud out of the hole, but as I got into this one it got pretty deep(not to deep just a really good hole)and really gooy so I opened it up and thats when it started the boggin and sputtering. I didn't have any smoke. After it recovered I got back on it and all was fine, and it pulled on thru. That should answer questions about how I entered the mud. Do any of you think its anything to worry about? Like I said I went back thru the same hole several times and rode all the rest of the weekend with no other problems.