At the end of my rope....

[CarlWilliams]

I have a 96 Sportsman 400, I bought the machine to plow my driveway with. It needed "a little" work, which turned into drive chains, bearings, sprockets...the whole nine yards. So here is the problem, there is an issue with the idle, I know this has been beaten to death but I can't find the same issue anywhere, when I give it a little gas it takes about 10-15 seconds for it to come back down to a somewhat normal idle. Also when I try to adjust the idle screw I can get it to drop or raise the RPMs but I can't get it to stay at the right spot, the slightest turn of the screw and it is to high or it stalls out. Here is a list of what I have done/tried so far.

• Check compression = 100psi
• Pull carb, tear completely apart, clean, reassemble
• Adjust Throttle cable/ETC switch
• New plug
• Monkey, Monkey, Monkey with different wires, hoses tubes

I have tried with the air filter on/off with no difference. I had the machine idling good but, the ETC switch was open when idleing, I also had the idle screw cranked in as far as it will go, and then some, when you hit the throttle, it would close the switch, and the machine would accelerate. This is not the way it is supposed to be and I had a small problem with the switch not opening and giving me a stuck open throttle situation. I hope my explanation is as clear as mud. Please help, I dont know what else to do. Thank you!!

[Bruce!]

Welcome to the board!

[Russ C]

crank case seals are bad and sucking air, like a vacume leak, 2 strokes are bad about this

[polman500]

I would tend to agree with Russ...one other thing you might check first is the carb boot sucking air. Get it running and spray a little carb cleaner or ether around the boot to see if it speeds up.

[factionfx]

I am curious how this thread turns out. We have a modified 250 trailblazer that does this. I have been under the impression that it is actually the throttle cable sticking a little bit.

[CarlWilliams]

Thank you to everybody that replied!! Here is what I came up with, using your suggestions I tried spraying starter fluid in, on and around different parts of the engine, it never gave any indication of an air leak as the RPMs did not jump any, so after more frustration I left it for the a couple of days. I have always turned the fuel switch off when I left it for the day, but I had forgot the other night and noticed a puddle of fuel under the machine when I came back to the garage, after some searching I noticed it was coming from the overflow tube. I bought a new needle and seat and threw it in real quick and this greatly reduced the high idle problem, but did not solve it, I adjusted the carb choke and Idle screw and after a few minutes of adjusting, I was able to get the idle near perfect!! the new needle and seat helped, but I think adjusting the choke cable made the biggest difference, I don't know if I am actually chiking the machine off in order to maintain the idle but, it runs giid and idles good....Thanks again for the help.