sled runs like garbage - intake backfire?

[indy_500]

Sled's a 99 Polaris XC 700. Sled takes off fine, no bogginess whatsoever. The minute i let off the throttle, it gargles and sounds like an intake backfire. I rode like it all day. Plugs look good. I even put in new plugs halfway thru the ride. Could it be the diaphragm in the fuel pump? Or possibly a burnt reed valve? Stock jetting is 190 mag/185 pto but i'm running 190 both sides since the pto looks to burn slightly leaner. 89 octane gas has been run thru it. Sometimes when i let off the throttle, it gargles and almost dies but then stays running. Carbs are clean, they're keihin round slides.

 

[sledhead25]

check your coil

 

[indy_500]

How exactly do i test it?

 

[Skylar]

Broken reed valve maybe?

 

[indy_500]

Broken reed valve maybe?

If i take the carb off, will i be able to look in there and tell? Do you think the petal could be burnt or the whole reed valve shot?

 

[lvr1000]

You say it happens when you let off the throttle? TPS. On cats you can bypass it to test if that's the culprit. Last three cats had that issue (After LOTS of MILES) Worn out plastic bushing.

 

[indy_500]

You say it happens when you let off the throttle? TPS. On cats you can bypass it to test if that's the culprit. Last three cats had that issue (After LOTS of MILES) Worn out plastic bushing.

Yup, only when i let off the throttle.

 

[lvr1000]

Yup, only when i let off the throttle.

Then check your throttle positioning sensor or whatever poo calls it.

 

[snootbiscuit]

hey indy, one thing comes to mind. I would definately check the throttle safety switches at the throttle block assy. !! if there is too much play in cables this could be it.... one switch has to make contact before the other breaks. cant remember the spec, not super critical, but when you get done, turn handle bars and make sure it doesnt rev up=too tight!if I remember you should have about .030 -.050" between throttle lever and throttle block

 

[snootbiscuit]

also, if you had a reed out, you will usually have a bog on the low end and prob woudln't idle too well. the switches come to mind cause you say it runs pretty well and that usually isnt the case if there's a reed out.

 

[rmk4ever]

Unplug the switches! & try it out

 

[wishbone]

I've even seen when the key switch goes bad it will do some of the same things. It used to be on the fuji's if you unplug the black wire with white stripe on main harness down by the fuel pump it bypassed all control switches. Not positive the liberty is the same.

 

[indy_500]

So can someone show me pictures or a part # from the parts finder on bristows? i don't know what to unplug.

 

[rp7x]

i don't know what to un plug

kill switch on handle bar ( under pad )

 

[indy_500]

kill switch on handle bar ( under pad )

just completly unhook it? by the way rp7x, i put on 70 miles yesterday and never heard the clicking once.

 

[glenn]

The plugs you are running are not the correct ones. That motor should run on rn57ycc. The br9es is not the corrct plug, I would start there and see what happens.

 

[trailshredder]

the plugs you are running are not the correct ones. That motor should run on rn57ycc. The br9es is not the corrct plug, i would start there and see what happens.

lol

 

[olsmann]

could be the amsoil?

 

[tomxc700]

Indy are the carbs in sync?

 

[ezra]

here kitty kitty kitty kitty