I am having a flooding problem on my son's scrambler. the symptoms. if you leave the fuel on overnight, you will lose roughly 1gal on the floor through the airbox. when it hasn't run for a while, it will start after a few seconds of cranking, and will idle for a short period of time. often you have to use the throttle to get the quad to start. you have to have the air box off to even get it to start and any sort of restriction will make the bike instantly flood and dump fuel into the air box. i have removed the carb, totally disassembled it, and cleaned it. i blew air through all the passages i could see to make sure i didn't have a clogged passage. i reassembled it with the parts manual on the polaris site as a reference. any help at all would be greatly appreciated!  

ok for the life of me i cannot figure out why this thing is flooding. it's almost like the float is stuck down. if i turn the fuel off and start the quad, the thing runs great. awesome power (for a well worn 90cc) all the way through the throttle range. and it runs awesome right up until it burns all the fuel in the bowl or i turn the fuel back on and it fills the bowl. then it floods as soon as you give it more than 1/4 throttle.

also, maybe someone could help in identifying the brand of mikuni. what do i look for or where do i look for a model number? i could buy a new complete unit for $250 - $300 from the polaris dealer (polaris p/n 0450924) but no way do i want to spend that kind of cash on an OEM replacement carb. can anybody recommend a good performance carb for a 90cc 2-stroke?  

man, 62 views and not a single person can offer an opinion?  

well since nobody responded and this does get spidered by search engines, here's some info for anyone who stumbles on this thread.

the carb is a vm16-438. after 20 or so tear downs, i gave up. i tried to locate an oem replacement outside of polaris, but the only one i found was located in the UK, and would cost just slightly less than replacing everything from the reeds out. so i ordered a kiehin pe24 carb with koso race intake/reed cage/ boyesen reeds, throttle cable and uni air filter from www.reimerminiatvracing.com for $215 shipped. you have to contact the site owner to place an order, as he tries to prevent people from ordering things they don't actually need. he is working on a new site now, so you'll have to contact him reimeratvracing@yahoo.com to place an order and discuss what he has available. of course, you could probably search the website on google and link into his parts catalog like i did, but i'm sure the new site will be ready soon.  

Sorry man i didn't see the post this morning when i got on before work.

the 90cc atv's from polaris i believe are all Taiwanese atv's made for polaris.
that being said you'll probably run into a few problems with them.

have you checked to see if the needle valve had the rubber end on it and it maybe came off and lodged in the housing causing the needle valve to hold open?

check out rjatv.com Johns probably got a better price on the carb you are looking for.