Having Issues need help

[chain0906]

Hey guys im new and having issues with my 85 Honda atc 350x, ran fine one sunday then sat for a week and went to run it again and now it wont idle and has no low end power but high end is fine. smokes white when first starting for a few minutes then fine, just rebuilt carb with new jets and still no fix and cant find much info on these 3 wheelers. any ideas would be greatly appreciated thanks.

[wonderboy]

Welcome to 3wheelerworld. Download the service manual. It is tough to really troubleshoot some things without the documentation.

There are a few places you can go, but I'm partial to:
http://www.kb0nly.info/ATC/index.php?dir=

I say work on the fuel system, but it could also be ignition. You rebuilt the carb, but it isn't clear when people say that what they really did. Just pulling out the old jets and putting in the replacements isn't a rebuild. You'll really need to make sure every passageway in the carb is clear. Just a hint, almost every opening connects to another opening somewhere else. Spray carb cleaner in one hole and you should see it come out another. Compressed air helps clear out the passageways too.

Another simple thing to do is make sure you have very fresh fuel.

[350for350]

I used to have problems with mine. Every once in a while, it would foul a spark plug. It gave no sign while riding, it just wouldn't start the next time I wanted to ride it. I finally found out that the 138 main jet that was in it was actually smaller than the 135 I bought from a dealership for higher altitude. I replaced it with a 138 from the dealership and I've never had a problem with it again. Maybe that would be a place to start.