I have a 2003 Polaris Trailblazer 250, oil injected, that smokes incessantly (much, much worse than my other trailblazer) and floods easily. If I take the airbox cover off (with or without the air filter) after it floods, it runs great but will not run with the cover on after it has flooded. It starts fine, and idles great but still smokes badly. Anyone have an idea what the problem might be?

 

You pretty much solved the problem with the air box, if you increase the air flow and it runs better, you have way too much fuel going in. Either your float is sunk, or misadjusted, so the level in the bowl is dumping raw gas into your engine, or the needle and seat is shot or full of dirt, letting gas flow by and overflowing your bowl. The extra smoke is the unburnt gas flooding your engine, leave it this way too long and you will damage your engine, the extra fuel will wash the cylinder walls and fill your crankcase, and wash out all the lube for the bearings/cylinder wall.

 

Thanks so much for your help!!! So...do you suggest that I replace the floats, the needle, and the seat? Otherwise, how do I adjust the floats? Also, do you think this could be caused by low compression?

 

I would start with a good carb cleaning, making sure to take out the main and pilot jet and make sure they are clear, then remove the needle and seat and check for dirt or excessive wear, could just need a good cleaning to seal up again. Unless your floats are sunk (full of gas so they dont float anymore, they should be good. Let us know how it runs after a cleaning.