I am having problems with my 2000 Scrambler 500. It won't idle. I have tried setting the idle up and down and I have check for holes in the disphragm. What else can I do? A friend suggested maybe a spark problem?

I don't have to much experience with 4 strokes but when my bike is not running well the first thing i do is put in a new spark.Be sure the spark is gapped correctly and that your bike is warm before trying to ajust the idle.Good luck.

RR,
heres a thought... will it run as long as you keep your thumb on the gas?.. If so, check your ETC Switch adjustment. Its located under the thumb throttle on the handlebars, If the contacts touch, it will kill the engine.. (safety feature)

Adjust the ETC!

since you are in PA and the weather has turned colder....
try this, adjust your throttle cable slack. my sportsman did the exact same thing when it got cold out. take all the slack out of your cable by turning the adjustment about 2 or 3 inches down the cable from your thumb throttle.

If it runs but will not idle it's the cable adjustment (take the free play out) Roll back the rubber cover 6" from the throttle on the cable and adjust it from there. When I brought my new HO home I had the same problem of “runs fine but wont idle”. I would drive down the street and when I let off the gas the motor would backfire and stall. All it took was one turn on the adjuster to get the slack out. I believe this is a future built into the throttle incase the cable breaks or sticks? Some one else may be able to shed some light on that.

Hope that fixes it for you, they are not fun when they are not running!

Mark

my 98 sport400 wouldn't idle either. u could crank it to let it warm up and after about 5 mins it would cut off. my dealer fixed that when i had to have my transmission rebuilt but it still won't idle at all in choke, as soon as the engine quits revving it cuts off. i don't get what's wrong cuz my sister's will idle in choke, 1/2 choke, and out of choke.