I have a express 400 that trys to start then dies if you let it sit for a few minutes it does the same thing. then sometimes it will start but you have to rev it up to keep it running coupleof questions how do you adjust the idle screw and air screw and and can someone show me a pic of how the the throttle cable should fit into the slide . how do you adjust the the throttle cable on the handle and how much slack should there be in the throttle cable on the handle

Thanks

 

If the thumb lever has more than 1/8" slack,pull back the rubber boot at the throttle housing and loosen the lock nut. Turn the adjuster in or out until the lever has about 1/16-1/8" slack. The air screw(small slotted screw) sets between 1 1/2-2 turns out from a lightly seated position. The big knurled **** in the center of the carb is the idle adjust. Just have it to where you have a constant idle. If it won't stay idling,becomes hard to start,it may be compression related and none of this adjusting may help. Checking compression is what I'd do after this.
If it shows 120 psi or less,could be time for top end work,crank seals.

 

the top end has been redone and has great compression

 

can you show me how the cable attaches to the slide in the carb

 

How about a service manual,can save my fingers.Index of /ORV Manuals/Polaris/1996-1998 - All Models

 

i took carb off and adjusted like you said and it will run for a few seconds then dies what is going

 

Okay.. Back to the beginning. You said it has new top end. Is that all that was done to the machine?

 

yes

 

Did you replace the crank seals? Has the carb been cleaned,new carb kit,etc? Fuel supply good? Air filter new/clean? Did you bleed the head after everything was back together?