carb problem 550 polaris

[j57snow]

my brother picked up 2000 550 reed case fan super sport not getting flow/vacuum on one carb. I don't think its with the engine/ignition because we swapped carbs between cylinders and same thing just other cyl also swapped fuel lines from pump to each carb with no difference any ideas it runs but when you put your hand over good carb kills engine & the bad carb you feel little vacuum but keeps running. he dissembled & cleaned both carbs the non working one had the choke stuck open but thats been cleaned & freed up.
any ideas ?

 

[fredster]

Is there gas getting to both carb bowls? Wondering if the float/needle is corroded/jammed in such a way that no fuel is getting in the bowl? Did you verify that the float assembly is working on the bad carb?

Another way to tell is to put new plugs, start it up and then check them. The cylinder not getting fuel will have a cold plug with some oil on it. The cylinder working will have a warm/hot plug.

If you go have fuel in both bowls...does the 2nd cylinder start to fire if you rev it up? If that is the case it is an issue with the idle circuit only and not fuel delivery to the carb.

Sounds like you need to tear apart those VM carbs a little bit more. Good luck!

 

[bouncer]

Needle is stuck in the seat. Try tapping the float bowl with a screw driver handle while the engine is running.

 

[j57snow]

thanks for the input blew it out with air & recleaned it,needle & seat ok probably dirt in idle passage, seams to be working now, thanks again

 

[fredster]

That is excellent! Time to ride!!