I have a 2006 sportsman 500 ho (carburetor) that will not start cold without holding the throttle. I have checked the choke plunger and used ether to check for air leaks and found nothing. IT runs great when warm until, I brought it in for service and had a jet kit installed and now I am having more problems. I told them to put it back to stock. I have also noticed that the air cleaner is getting really dirty (blow by) but the compression is good. I am at a loss as what to check next, but my buddy has the exact same quad and it starts and runs great! Help.

 

w/ the stock jetting it still doesnt star or idle good cold? have you turned up the idle a little? how does the plug look? wondering if its getting too much gas and flooding it out when the cold raw gas goes in although it really isnt that cold yet.

 

It will start cold if I hold the throttle regardless if the choke is on. Originally thought it was a plugged choke tube. I need to check the plug whe I get it back, but it runs great when hot so the plug was ok before. I gave up and brought it in but they have had it 4 times and it is still not working. They up the idle and I have to turn it down when I get it back because it speeds up when warm over 2000 rpm.

 

wonder if they changed the needle clip or something or didnt adjust the fuel screw when it ws rejetted?hard to say, but if put back to stock setting it should be back to running fine as long as it all went back to correct setting.

 

So I am back to stock and it is running better when warm. I am still having the cold start problem. It is just as easy to start without the choke as with. The choke plunger is working and the choke tube is blown clear?? Do you think the crank by pass is the issue. I have not checked the compression but it idles great when warm????????

 

Remove the brass cap from the air screw, the screw is on the bottom of carb, to remove the cap you have to drill it and screw a metal screw into it and pull out cap with vise grips, see what fuel screw is set at, should be 2.5 turns out, Ive seen some completly shut, makes them hard to start.

 

Is that the same as the pilot screw???

 

there are two kinds of pliot srews, a air ,and fuel one air srew is on older carbs on back of carb and fuel is on the front where the bass cover is your best thing to do is pull that and go a head and Clean the carb