I purchased this atv over the winter and all seemed OK. It would run really rough until it got warmed up and then would run OK except it would hesitate. Decided to livewith it until it got warm out and I could work on it. First thing I did was change the spark plug and it ran extremely well. It set for a while and the next time I ran it, it would not run good at all. It boggs down through the entire throttle range. So last night I was chasing a horse around and all of the sudden it started to run perfectly....for about 10 seconds though!!! Then I ran out of gas!!! That got me to thinking that the mixture is way too rich since I can turn off the fuel line and repeat this over and over. My biggest problem is that I know nothing about atvs and I don't have a manual so I don't know where to start. I can generally fix just about anything with regards to autos, tractors, etc. I just don't know where to start on this one.

Thanks,

 

Check jetting,depending on area should have betwen a 210-240 main jet,BUT if bone stock and set up for your area,suspect needle and seat also for wear(dumping fuel) Polaris richened up the Scramblers for the simple fact of what they knew most people would do with them! Run a lot harder than the 400 Sportsman. I even had to drop the main on a lot of Sportsmen from 210 to 190 to make em run good at our level (600 feet elevation) without blubbering in the summer!

 

I'm at 1600 ft, but I bought it from a local guy who had it for many years so I'm assuming it was set up correctly. It was rebuilt once by a guy I work with so I know it was done right. I checked compression and it was OK.

Also is pouring out a lot of smoke. Much more than it used to so I am suspecting it is what you are saying a worn needle and seat.

Now how do I get to the jetting to check? Start by top of carb by taking off air filter I am assuming?? What am I looking for?

 

Remove the carb, remove the bowl from the bottom of the carb, there will be a small brass hex (6mm). That is the main jet, read the # on the side of it or bottom of it.

 

I took the large nut off the bottom of the bowl. There is a small brass nut there that reads "250". I am assuming that this is the jet number. Should I just buy another 250 or should I buy a 250 and some other numbers to try. What do you suggest?

 

Jet should be good as long as clean and can see daylight through it, I would check/replace needle and seat plus make sure float arm is level with body of carb, I have leaned em down over the past down depending on how they ran,BUT If you are tough on the machine 250 may still be ok. This is not an absolute science,JUST have to see how your machine runs after needle and seat.IF you are a "putting" around sort of guy,no wild wide open stunts,you can drop jet size to 240 with no harm plus slide needle can be dropped one clip. If this is confusing a manual is a must! OPT

 

I guess next trip will be to the dealer or have a look online for what is available.

I was planning to buy a manual anyway. Where is a good place to buy?

 

Don't forget to have a good clean air filter!!!!

 

dont forgt to check your clutches.... I was sure my 96 had carb problems which itd did but I found out today my rear clutch needed new buttons and the helisx smoothed up. my fornt clutch needed to be rebuild. looked ok to me but my polaris mechanic pointed out some wear that I couldnt see. and he said it would cause a lot of my problems which was no mid range.

so Im having him rebuild my clutch we will see.

 

The only thing is that it will run exceptionally well for about ten seconds after cutting off fuel. Any other time it is bogged down from idle to WOT. Points me to the carb, but let me know how yours turns out. Checking clutches is definitely on the list of things to do.

I took the unassembled jet and piston/needle and put them together. Seemed like a lot of play there. I know it can't be totally shut off or it wouldn't idle. It just seemed like a lot. What should I expect here??? Seems like I shouldn't be able to move it around that much. I don't see any ridges on the needle

More info:
(1) poured gas in the float bowl and both floats came to the top and were floating with half out of the gas - considering this normal unless someone says different

(2) forgot to mention that when it was running, turing the idle screw all the way in or all the way out made no difference - seems like this may indicate it was flooding??