1999 Polaris Scrambler 400 4X4 getting too much oil??

I picked this up a few weeks ago and it ran like crap. It was bogging down and had poor acceleration. The stock pipe was full of carbon/oil and the plug was fouled out(black). Seemed like it was running rich. I rebuilt the carb, put on a DG pipe and a new spark plug. It fired right up and ran great with awesome acceleration w/ no bogging for the first couple hours. It wasn't bad, but I noticed it started to bog down a few times and could see oil seeping around the end of the brand new pipe. It appears to be getting too much oil, but isn't smoking much at all for a 2smoker. Does this make sense? I DO NOT have an oil block-off plate installed. Any ideas would be appreciated.  

Is there an adjustment I can make to the oil pump and/or throttle cable to change the rate of oil flow to the engine?  I haven't checked the compression yet... maybe it's time for a new top end?