2000 polaris 90 scrambler

[smitdog]

I bought this ,it had very low compression .put new cyl & piston on it. it runs for a little while ,then seems to run out of fuel it does'nt really back fire,just slows then quits I checked for fire it has fire after it quits.polaris mechanic told me it should jump 5mm which it did when i checked it cold, but is pretty much orange replaced cdi box,bought stator but was not the right one.checked & cleaned carb.It has electric chock not sure how to check it.Could it have anything to do with throddle safety switch? Exhaust clogged,or fuel tank clogged .Cover over fan is missing on rt side I thought it might be getting hot,but it does,nt run long before it quits running.Im getting fan cover for sure.I did not replace coil yet but will.Starter is junk & battery is dead . not sure if that has anything to do with I dont seem to think it should. HELP

[Sc0tt]

When it stops running can you start it back right then or do you have to wait awhile?

[GEARHEAD01]

it sound like someone just disconnect the vower and then puts it back together. does the atv have a kill switch. if it doues it could be shorting the quad out and when it cools it can run again. is the machine being ridden when it stops running.

[DirtDemon]

Have you checked the compression since you replaced the cylinder and piston, sometimes alot of compresson can be lost from poor valve seating. Also, your spark should be blue, an orange spark is usually evident of low voltage. You may just have a bad coil, or poor connection between the coil wire and plug boot. I would recommend getting a service manual and performing any direct resistance tests listed in there for your ignition components.

[smitdog]

Thank's for the reply's.

[GEARHEAD01]

i would clean up all of your ground connections and positive connections. check all of your electrical circuits. i would suspect you have a bad connection or a weak battery or a poor voltage regulator. these places are good places to start with poor spark. and as for your original statement the coil will cause the problem. coils make connection when they are cold and break circuit when the get warm or hot. that would give you the just shut off symptom.

[raingerrick]

i would start with new battery.and continue with other suggestions.rick

[GEARHEAD01]

I would not put a new battery in and waste money parts replacing. i would take out the battery and fully chrarge it. pick up a load tester from house of tools or a cheap tool place. load test the battery and decide from there. your battery under load for 15 seconds should not drop below 9.6 volts for a 12v battery regardless of the size. if it does replace it. becides your time/labour is free. i would check all of your connections for tightness, also put star washers underneath the wire connector and the part you are attaching to. this will ensure good connection. you may have to many voltage drops in the circuit causing you to loose spark. I do not believe in just throwing parts at things. it gets to costly. they teach you in mechanics classes to diagnose the problem first. I would start there.

your friendly neighbourhood mechanic.