[Resinat0r]

Ok so i have posted about 4 times and nobody has really helped me.. anyways. I have a 1985 polaris indy 400 l/c , i bought it last year from a guy and it barly ran.. since then we have rebuilt it twice , changed pretty much everything in the motor including fuel pump , fuel lines , carbs , jets , plugs , and now finally the cdi .. no luck. the problem is it starts up and idles perfect , i let it warm up about 3-4 minutes and then when i go , i only get to go about 2 minutes and it cuts back in power , like its running on 1 cylinder, it barly has enough power to move and when i pull the plugs 1 is very wet ( assuming its not fireing ) but we put a brand new cdi so i dont understand. so point being when it warms up it dont run. Can sombody PLEASE help me. im about ready to burn it where it sits.

 

[RXL]

I didn't see you mention anything about coils...... sounds like you have one crapping out.

 

[Resinat0r]

no but im pretty sure the 400 coil is in with the cdi box

 

[jrscars]

try this, you are saying the one plug gets real wet, which sounds like either electrical, as in it quits firing, OR fuel... flooding the cylinder

So clean up the plugs, dry out the wet cylinder, and swap the carbs, right to left, left to right and fire it up, when it dies this time see if your wet plug is now the other cylinder, if it is, you have a carburetor problem.

 

[BC_Dan]

Before you change the carbs as jrscars suggests, try just switching the plug wires from side to side. If the problem follows the wire, it's an electrical issue. If it stays on the same cylinder, then do the carb swap as he suggests. That will rule out electrical before carbs, and switching the wires is simple and quick.

(there is no firing order on the sled, both plugs fire at the same time. This is called a "lost spark" ignition system, each wire fires twice per revolution, one spark fires the fuel, the other spark is "lost" because the fuel/air is not under compression and there's nothing to ignite when it sparks.)

 

[Resinat0r]

Its not the firing becasue today when it wasnt running right we pulled both sides ( plug wires ) and it never shut off soo it cant be the firing. Carbs maybe? thast what our local dealer said.

 

[jrscars]

swap the carbs side to side, I have a feeling when it does your going to find the other cylinder is all wet, Then my guess is a needle and seat not sealing

 

[indy_steve]

my old 400 did that to me once. one of the main jets actually fell out. check the carbs