My friend and I were riding last weekend and his vinson 4x4 auto started acting up. We were cutting across this field fast and the vinson started sputtering and began to back fire slightly. We stopped, let is idle and after a minute it ran fine. A little while later it did it again; going fast down this road but this time the sputtering didnt stop. The vinson will idle fine but once you give it any gas it sputters and dies no matter what gear you are in. So we let it sit over night and we went to try riding it again and it does the same; idles but dies after goiving it any gas. We took apart the carb, air filter and cleaned it and checked the fuel lines and we cant fine anything wrong but the problem still persists. I read some where about a bad petcock problem with these but i am not too sure if it has been changed or addressed by a dealer. Anyone have any idea what it could be? Any help would be great, thanks!

 

If it runs better with the chock on it is a fuel problem. Turn the petcock to PRI, the fuel should run free. Also there is a float bowl drain screw on the bottom of the carb, make sure fuel runs from there also. Where the fuel line hooks to the carb there is a small screen in the tube. Use a soft wire and some carb spray to clean it out. Cut the line from the petcock to the carb in half and install a filter. Replace your spark plug.

 

Okay i'll give that a try.... if i remeber correctly having the chock on made no difference, if that changes anything. THanks for the input

 

Well it looks like everything flows fine and has been cleaned, putting the choke on makes no difference either. We read somewhere that it might be a clogged spark areester, hopefully we can work on the tonight.

 

HAVE YOU FOUND OUT THE CULPRIT TO THIS PROBLEM, I JUST HAD THIS HAPPEN TO ME THIS LAST WEEKEND, KINDA GOT IT NARROWED DOWN TO THE MOISTURE ENVIRONMENT, BUT CAN'T PINPOINT. ANY MORE IDEAS, STILL TROUBLESHOOTING, SAME BIKE 2003 VINSON 500 AUTO...

 

Well we tried alot of thing to no prevail. The quad is currently at a suzuki dealer getting fixed. We were told it could be something in the very inner workings of the carb(my firend didnt feel comfortable with me rebuilding it [img]i/expressions/face-icon-small-sad.gif[/img] ) or something about the valves. I will definetly post if up when we get a definet answer

 

Please do let me know what you find out. I went out riding yesterday after changing my spark plug and cleaing air filter, prior to riding i bought some carb cleaner called kawa-clean from dealer, ran all day but in the beginning my vinson still was a bit boggy, then about 20 miles into ride had a small backfire and then my bike started running normal, good horse power, lots of power, etc... Not so convinced it is all better because I am still suspicious of wet conditions since I had noticed that a majority of the times i lost horsepower was in the rain and going thru water holes, I will be going oiut again this weekend and it will be wet so I will also update you to see if all is better, thanks for reply..

 

I think you guys are getting trash in the carbs. I had a yamaha that acted the same way. When it would backfire it would dislodge the trash in the pilot circuit in the carb and all would be ok for a while till the trash would get back in the pilot circuit. Does the atv run better if it is choked when this happens? Try cleaning the carb, draining the gas, and install a fuel filter.

 

I agree with CamoZuki, probably dirt in the carb / fuel system.

I had a very similar proglem on my 2004 Eiger. It backfired, and lost power then would clear up for a while only to come back when I gave it alot of gas. (usually hill climbing or fast excelleration) I cleaned the filter, carb, gas tank etc and could not fix it.

I finally brought it to the deal and the was a small piece of a pine needle in the carb. ( they actually saved the piece and showed me). I guess it was floating around. It would block the jet or hose or filter and reduce power and then move and it would run fine for a while. I assume the reason I could not find it was it was floating around.

 

Exactly!