I'm at my wits end with my 98 Xplorer. I purchase it used a little over a year ago as a project. Redid the top end and cleaned it up. Over that time, it had an issue fouling plugs, especially when under load (i use it for hunting and fishing. No trail riding or racing). It fouled in deep snow, in deep mud, and had typically been extra smokey. Last December, it just died. Since then, I replaced the crank shaft seals, water pump seals and gasket (i found coolant in the front 10w-30 oil) I still had issues, with my compression being 90 psi. So, I pulled the head, piston (some damage done to the lower section of the piston), and jug, brought it into a local speed shop (Told me the damage could have been due to not warming it up properly) to have the top end redone, again (new WSE piston and rings, boring, and the head was 'leveled'. I also bought an All ***** rebuild kit for my carberator. All new fluids (Polaris AGL, 10W-30, coolant) and new brakes while I was at it. I also bought an oil pump block kit.

After getting it all back together I decided to give it a start. I had very low 2 stroke oil level , but had put maybe a quarter tank of 32:1 mix in the tank to run with it. Third pull, it started. Pretty smokey..as expected...but it started. I let it idle, using barely a quarter of throttle for two 3 minute cycles, Sunday night. Today, I got home, third pull, started. I let it idle for maybe 3 minutes. I then attempted to pull the oil pump, but I had screws stripping so, after some consideration, I decided to wait on the oil pump delete, hooked it back up, put some Lucas Semi-synthetic 2 stroke in the oil tank, drained the premixed gas, put in some 'regular' gas. The ATV turned over and ran much better. Very little smoke, ran geat, and at one point, idled on its own, (as its never done that for me, previously) until it died. A couple pulls had it sputtering again, or it would start and run for literally 3 seconds but then, die. I pulled the spark plug. Fowled. I put in a new but used plug in. It sputtered on occasion but nothing. I pulled the plug and it was again fouled. This happened 4 times, with two of the last sputters had me giving about 3/4 throttle to keep going, before it died. Checking the carb, I found it oily around the boot and the inside area between the boot and the air filter in the air box.

Any ideas? Ill be picking up a fresh spark plug or two tomorrow, hoping that will help. Also, why do i continue to feel carb settings are creating this issue?? Im not 100% sure its set the best, but I did do the air screw and the throttle screw to what was suggested in the Haynes book.

Thanks in advance, guys

 

Hello, I am in a similar boat as you. I bought a 1994 Polaris Sport 400 2wd. And got it running really good, but I have oil in my coolant and need to fix that.
but if your machine is a 2 stroke, you should have Reed valves right behind your carburetor. And what I did to mine helped mine run better.
I can send you pictures from my climber service manual?