Hey all, I'm new to the forums and this is my first post.

Anyway, a friend of mine had an old 90cc 2 stroke sitting in his garage and his parents decided that it was taking up too much space and gave it away... i was lucky enough to be on the receiving end of that one... although i'm 6' 1" and 190 lbs i thought itd be a kick to just cruise it around every now and then.

I understood that i'd have to put some work into it, as it had been sitting about 4 years with fuel in the tank.. so before i even tried to start it i tore the carb down and gave it a good cleaning. after a good deal of cleaning (3 days) i got the thing to start and idle just fine, but as soon as the throttle is depressed it shuts off. i know the carb is flowing freely as i've tested that in several different ways.

i suspect it may be an electrical problem. it had a blown fuse which i replaced along with the battery, but the electric start and lights still do not work. it starts with one kick and will idle all day long.
does anyone have any ideas? i figure its at least worth a couple hundred bucks if i can get it running.... i'm a poor college kid haha.

i've got a lot of technical experience, so dont be afraid to throw out the complicated stuff... i just dont have the cash to take it in for repair.

 

Sounds like the main jet still not clean? did you flush tank? Did you check the little screen in the fuel valve bowl for trash,the air box,filter and air box tube for blockage? Did you replace/clean needle and seat in carb,GOOD fuel flow to carb? BPR7HS plug? Water in fuel? Lot of questions I know,BUT can be any of them. Blown fuses are common since a lot of people dont replace batteries,they just kickstart these machines. Doesnt sound like electrical since it runs (stators going out are the most common problem,no spark condition) Exhaust open,feel pressure ???

 

i completely tore the carb apart and cleaned it piece by piece. there is good flow to the carb and the tank is clean. i wonder if maybe there is still some build up in the carb's internal plumbing. the spark plug is good and the screens and filters are clear.

would you happen to have any idea why the electric start and lights wont work even with a fresh battery? thats what led me to believe it might be an electric issue.. there is a wiring harness running from the carb (5 or 6 wires) that hooks up to the rest of the atvs electrical. never really seen that before but i figured that might be the problem as i spent 3 days scrubbing the carb clean...

 

it does the exact same thing with the airbox and intake tube completely removed, so i know that cant be it either. maybe i should soak the carb overnight or longer in seafoam to see if theres something i missed?

 

Exhaust carboned up? have had this happen,will exhibit same symptons as you describe ?
have had em just idle and die with throttle. just a thought? Plus depending on model there is a little tube with a red plug in it on top of carb, which can split and cause a lean condition. Elec chokes if so equipped DONT help one way or another! ONLY if plunger is frozen. Newer models went to manual chokes! The wires you are talking about probably are to the cdi. Only problem I've had with them is on the later models with the small restrictor plate at one end that wasnt removed,LIMITING rpm.

 

haha... i thought about that too... i removed the muffler.
same result.
:/

 

Keep at it! Process of elimination! may turn out to be something simple!

 

yeah i'm still working on it.
havent had a lot of time with work and school, but i'm going to spend the weekend trying to get it running. i'll post any updates or if i make any progress.
its a frustrating little son of a gun.