Just gopt a 2002 ac 90cc it wont run unless air fuel screw all the way in and still backfires and dies .Can anyone help

 

My brother also has one of those, we got it new and now we are selling it. In 02 and even some 03s they had issues with the air intake boots dissolving and falling apart and rubber pieces would get sucked into the carb. When we got my bros my dads friend who owns the dealer gave us a new boot and carb to put on before we even took it out of the crate. So i would clean the carb get a new plug NAPA carries them check and make sure the boot is not falling apart. The other thing that happen was the packing in the exhaust silencer itself kind of fell apart withing the first 10 hours of use witch blocked the exhaust flow and choked it out and acted as if it were running out of fuel and it would die and you could not move it at all it just bogged and died so we pulled all the packing out of it and its not very loud at all I think my weed whip is still louder but that fixed all of our problems try all that and see what happens hopefully that works these 90s dont usually have many problems, we took all the limiters out of my brothers and it does 30mph now and it does wheelies. Oh and the 90cc two strokes are a lot faster than the 90cc 4 strokes when all the limiters are taken out.

 

What limiters are you talking about and we found out our problem was bad rings had no compression also is it normal that when you give it gas it takes a second or two to rev up one more thing in the book it says to set float height at 1/2 inch but from where Thanks for all your help

 

There is a limiter in the clutch that will not allow it to shift into hight range so it will only go like 8-10mph, I took this one out and then they have a limiter in the throttle block on the bars, we took that one out as well as the clutch limmiter, I will have to look at it again to tell you more about the limiters because I took them out back in 03 and I dont remember exactly how they worked but once you remove the limiters they will do about 30-32mph on a paved road. As for the bog yes that is normal and mine has done this since new but got worse as it got older so I replaced the plug and now she starts like new again and the bog has gotten a lot smaller but yes all the 2 strokes have that slight delay, pin it and it should only bog for about 1-3 seconds around there and then the rpms will jump up, with a smaller person on it the bog is less, I think it may be a jetting thing but I would not mess with the jets, I noticed that if I ride it and pin it before it gets totally warmed up the bog is not there and it just takes right off but they do wheelies like crazy with a bigger person on them with no limiter, I can just sit on it and pull back and do a wheelie. as for the float height I am not sure to be honest with you, I just take the carb off, clean it and put it back on, Im not sure about the float deal I will have to look into it for you, I do not have a repair manual for mine, I have just been doing this stuff on my own just from the knowledge that there were limiters I could take out and I just found them and took them out, and thats what I do is repair atvs and snowmobiles and make them perform. I will have to check on the float deal for you. Hope this helps

 

oh and don't forget to fill and check the oil, not good to run out