I have'nt looked at mine that well, just bought it also, some carbs don't have an air screw, just a pilot, but on most of my sleds and bikes that have both, when you turn the air screw out you are letting more air in ( leaner), if you turn the pilot screw out it's letting more fuel in ( richer ), if you gotta pump the hell out of the throttle and choke when starting, it sounds like fuel starvation, have you checked fuel flow, pull the hose off and see if it's flowing nice, could be a dirty, clogged petcock or filter. Another thing comes to mind, float level setting, could be the bowl is dry!

 

if i remember correctly if the screw is on the air box side then its an air screw. if its on the motor side, then its a pilot screw, this one is on the airbox side.
the fuel line does have a filter in it. ill try bypassing it tomorrow and see if that helps but it would seem odd that the bowl wouldnt be full because once it does start then it will run until i turn the choke off. then it bogs down and dies but i also havent really adjusted then air screw besides then normal 1 1/2 turns c/cw.

 

I would say on a 2000 250 that is hard to start may need rebuilt. Check your compression. Once compression gets too low it will be very hard to start and will not run well. Thats why they had the idle up so far so they can keep it running. You may have been taken on this one.

Check compression and get back to us.

 

I'm afraid TooManyToys may be right, but you said in the first post you changed top end gaskets, I assumed it was apart, you put new rings, def check the compression first, then move on, the reason I thought it may be fuel flow is because it only runs with choke on so the choke is trying to pull the fuel in, same thing with rings, low compression will make it hard to pull intake, crank seals will do the same. Hope I'm not confusin you, definetely would like to know the outcome, hope it's a cheap one.

 

im in the process of making a leak down tester kit for it..ive been eyeing the crank seals from the start. i didnt put a new piston or rings in it i have 2 jugs for this thing. one std and the other is overbored. i bought a top end kit for the over bored jug but they sent me a std piston/rings. sent them back two weeks ago and im still waiting for the correct piston to come in. i got tired of waiting so i just put the old parts back in without a compression test. hopefully today i will get all the parts left for the leak down tester

 

well i FINALLY got the derned thing running...i bypassed the fuel filter..but im not sure if that was the problem or not. what i do know was a problem was a rookie mistake. i was moving the "E" clip up and down on the jet needle and the last time i did that, i guess i didnt get the clip all the way on and it vibrated off. i pulled the slide out of the carb and there wasnt a needle on it..looked down the top of the carb and theres the needle in the needle jet. put that all back together and put an overbored topend on and it runs just fine..im still not sure on the main jet calibration tho. i have a 165 in it now but the carb kit that i got and the jet that was in there with the stock bore is a 130. i only went up to 1.00 overbore. is this too much on the main jet or around the right number?

 

best thing to do is keep an eye on the plug and it will tell you if its running too rich or lean. sounds like it might be a little rich, which is better then too lean to burn it down.

 

well i took it out for a ride today..did fine except for one small problem...it lost power then died and got to lookin at it, and the oil line to the cylinder had come off. dont know how long it was off for but i checked compression it was fine. put the oil line back on and it still didnt want to start. got the messing around with the spark plug and in the midst of that, the wire came out of the boot. trimmed some of that away and checked for spark..wasnt getting any so i changed spark plugs and check spart again...was getting spark. put that plug in and it cranked up.

my other issue is its still hard to start...have to pump the gas while starting it and it will eventually start. also the idle is very iffy..i can adjust the idle so that it will run and i can put it in gear..go ride for a bit and the idle is high again. im kinda leaning to the throttle cable needs some lube on it, but is there anything else i need to look at? mebbe oil the slide up a little bit?