Textron Off Road ATV Forum

Yeah Randy.. they are all very critical and carefully chosen..  And.. carbies are not junk..  Just the wrong one for the job. Read the tests we do to check mixtures and settings.. See if anyone(any one qualified) suggests snapping the throttle open as a test.. on the type of carby you have.. If you want to snap the carby open, which is not a good driving technique, then get a pumped carby.. And you see those small holes stacked up on one tube.. that indicates it needs/gets a lot of enrichment as it comes onto the needle, which means it's running lean somewhere else.. slide probably. Not all acceleration compensation is richening, sometimes they run things rich, and then lean them temporarily or after attaining speed.

That jogged my memory.  The tube is how I know it's a 2-stroke carb.  I remember swapping that too with no luck. I thought I posted these pics earlier:   The 230s and 250s carbs are the same but look how different the 250s needle is.

I saw that "super tuning" manual, but there are better, more appropriate ones for you. Mikuni ones. I did a search putting the jap brands in front of technical training manuals and there were a few for sale, all hard copy though.. And yeah, you know the emulsion tube, and how some of them have small holes half way up them, well those are important, they mix air in, but they also serve as enricheners as the needle takes over.. they are part of the acceleration compensation.. Not all two-stroke engines have those holes. You should read the tuning process, the order of operation, and the tests.. Then you might have more luck.    

A blocked fuel filter or low fuel pressure could cause a lean mixture. Only at set speeds is probably significant.. I thought we'd sorted the model and got the right manual.. So what have you noticed about the bike that isn't as the manual says ?

Thanks, I haven't had the time to mess with it for awhile but I want to get it running right before hunting season. When I get the time I'll pull some of the covers off and go over the basics. Lean mixture? doesn't the ECM control all that. I haven't been able to find a service manual for this ATV. I downloaded several but they turned out to be the wrong ones. The closest one I found is a 2009, 450 AXI and that's been close enough up til now.  I looked at where it is leaking and I can see that someone has wraped muffler tape around that area and it has come loose. When I first got the bike I didn't hear any leaks and it is strange that the cough/spit thing shows up about the same time I noticed the leak. As far as the muffler being stoped up I guess that is a possibility but when I first got it I was looking at it because it was a tad bit loud for my taste and I could tell it was passing gas because I could feel it. Though I guess it could be partially stopped up but if it was stopped up I would think it would be boggy and hardly run. This thing has plenty of power and aside from the little spit every now again it takes off from a dead stop to WOT with no hesitation. Also when you give it gas and while it is excellerating you don't get these miss/cough/spit it just goes. I only notice it when you are just moving along at a set speed.