back firing

[xrcrash]

OK Guy's i need your help on this one. I have a 2000 xr 650r all stock with the honda hop up kit. i let it sit for about 4 months and when i came back to start it she started fine and idled fine but as soon as you move off the pilot it starts back firing and missing. So i think fuel is bad so i cleaned the carb changed plugs and put in new fuel half 91 and half 102 octane. still doing it so maybe i missed something, off comes the carb and i blow out all the vents, jets, adjust float, and pull off petcock and fillter. same thing, so to the shop i go and have them listen to it they say just what i thought it is not getting fuel. if that's not it, then the valves need adjusted. so i adjusted the valves.(they were not that bad). so that is where i am any help would be great. thanks

[Mountain Road Madness]

Did you check you air box, where you air filter goes. When we bought my wifes bike it had been setting for a while. When we got it home, I noticed that the power was down for some reason. I started checking everything and it all looked good. I pulled the cover off of the air box and it was full of paper and straw. I guess a mouse or chipmunk had made it a home. I couldn't believe all of the stuff I pulled out of the box. May want to check there. Hope this helps. ?

[xrcrasher]

Yep, he checked that. We are trying to double team the problem. I think most of the simple fixes have been tried, unless the gas is still contaminated. We hope it isnt electrical in a stator kind of way. (&%$#@!) ?? these Hondas are too reliable for a major problem! ?

[captb]

Does it run better with the choke on? if not I would check electrical connectors and grounds and unplug the kill switch, start it in the dark and look for possible coil or plug wire arcing to ground when it's missing, sounds like fuel problem but worth eliminating all other things before yanking the carb again, tank vent ok? Sure it's not rich the choke butterfly can stick even thou the lever operates ok.

[xrcrash]

i have unplugged the kill switch already i for got to say that. it runs worse with the choke on. tank vent is fine, i will check for the arcing

[Motosprtman]

1. verify the flow of fuel from the tank to the carb by turning on the gas and then placing the float bowl drain line into a suitable container, loosen the float bow l drain screw and fuel should flow from the drain line.

If no fuel flows then,

2. Remove the carb and check the float needle valve, If the float needle valve is stuck it will not allow the floats to refuel the carb and essentially shuts off the fuel flow from the carb to the intake.

[martinfan30]

hey is this the same motosportsmn from the xl page? whats up man? hows the new mods to your big red pig? later!

[wr450fyamaha]

Did you check you air box, where you air filter goes. When we bought my wifes bike it had been setting for a while. When we got it home, I noticed that the power was down for some reason. I started checking everything and it all looked good. I pulled the cover off of the air box and it was full of paper and straw. I guess a mouse or chipmunk had made it a home. I couldn't believe all of the stuff I pulled out of the box. May want to check there. Hope this helps. ?

one of the biggest reasons i stay with stock, that metal screen deters mice.....so hopefully they cant chew through that even if they take off the paper.....they can put a 2 inch hole in foam in about 4 minutes....they might give up on hard metal screen.