Pull your spark plug and check the color, grey/white is lean, rusty brown is spot on and black is rich.

 

Your kidding right. Running rich or lean has nothing to do with emisions. If quads had to meet stringent emision standards cars do they would all have closed loop fuel injection.

 

"Your kidding right. Running rich or lean has nothing to do with emisions. If quads had to meet stringent emision standards cars do they would all have closed loop fuel injection."


Actually he's not kidding, there's a label under the Predator seat the tells you it jetted for temps 40 and above, below that it needs carb adjustments so it's not set on the rich side from the factory.

Running rich or lean has everything to do with emissions, if the fuel isn't burnt it's blown out into the air through the exhaust commonly seen as black smoke. The optimum air/fuel ratio is 14.7 to 1, lower air numbers are on the rich end and higher air numbers are lean.....

 

Umm.... no I'm not. Nothing to do with emissions, wrong. If an engine is running too rich ( sucking way more than it needs ) it is wasting & polluting way more than it should. Personally, I don't give a rats rear. However, if you don't believe me.... which I don't think you do.... just take a look back at at the cars of the 60's- early 70's. High horsepower, gas sucking, exhaust belching. What happened to them????
If the fuel mixture has nothing to do with exhaust emissions, then why do we now have high horsepower engines that meet the emissions standards? Call me crazy, but it just might have something to do with the technology of more efficient fuel burning. A.K.A. leaner. Less fuel= less emissions.

 

If it isn't the burning of fuel that dictates emissions levels what the heck is it? I would assume since fresh air comes in, burns fuel and blows out the exhaust it must have something to do with the ratio and efficiency of the fuel burning. I am no rocket scientist so tell us what does effect the emmisions levels if it isn't how efficient the fuel burns.

 

By the way..... u dam_ right atv, snowmobiles, dirt bikes, weed-eaters, lawn mowers, etc. have to meet emissions standards. When I had my 400ex, in the manual it specificly stated, to conform to the current emission control standards, this machine is jetted lean & NO carburator setting adjustment is needed or should be performed. Thats why I piped, filtered, & jetted mine[img]i/expressions/face-icon-small-tongue.gif[/img] By 2010 if 2-stroke manufacturers can't meet emissions, you not see any 2-strokes available for public use. They will be labeled "for closed course competition only" which is stamped on most dirt bike exhaust already. Now unless you say something totally offbase again I'm done. Because argueing over the internet is like the special olympics.............. even if you are the winner you're still a retard!

 

I have a 350 two stroke and have to change main jets, one for summer and one for winter. Also have to adjust carb jets for high speed and idle. It is a pretty simple to do once you get it set up you just have to repeat it in spring and fall. The winter settings are not as good as the summer setup but it does the job with no bogging down and you barely have to use the choke.

I bought my 350 through a polaris employee when new and he gave me this info to keep it running strong in the cold months here in Minnesota. He also told me from his experience if you don't use a winter jet you risk blowing up the engine (circ 1991) when the oil injection feed was before the main jet.

jinks

 

I think your confusing running rich or lean with actual gasses coming out the tailpipe. Im not talking about just particulates but co2 ,N0,and everything thats burned along with it. Back in the days when carbs were prevalent they actualy had to run carbs them extra rich and waste fuel to provide a good reading out the tailpipe. Egr valves dump exhaust back into the intake to dilute and cool the combustion to keep some gas levels down. Of course were talking about a drivabilty problem which polaris should be handling since its a new quad.

 

O.K., I think everyone agrees that it's running to lean for the cold temps. I just had to say I like the photoshop enhanced backflip on wistechs pic. page. Looks just a little like a no-hander jump turned 180*, hmmm[img]i/expressions/face-icon-small-smile.gif[/img]

 

OK so reading this, i don't understand much. My somewhat related question (sorry to threadsteal) is that will running my stock sp400 (4stroke) in the cold hurt it at all. Power loss isnt really a problem, I just wanna make sure its not bad for the motor. It was about 3 or 4 degrees today and it seemed to be running fine.