Bike Only Runs With The Choke On

What would cause a bike to only run with the choke on? I did a desert race this weekend and after forty miles the bike wouldn't run unless the choke was pulled out. Could a blocked pilot jet cause this?

I got an 05 wr 450, stock needle, 48 pj, 168mj, baffles removed, Big Gun Exhaust blah blah blah

Yes, a blocked pilot could do it, in fact that is one of the most common reasons for a bike not to start after it sits for a while. The pilot jet has such small holes it is easy for them to plug up, with either dirt in your case, moisture after washing, or corrosion/fuel decomposition after sitting. The only other place to get fuel at an idle is the choke circuit.

Also the pilot air jet on the rear of the carb. may be pluged :)

I just got done checking my pj and I was amazed to find about a quarter inch of fine silty sand in the bttom of the float bowl drain bolt!!!! :) The race I did was pretty sandy in spots sio I'm assuming small dust paticles in the air were sucked in thru the intake side of the carb. I've heard of guys at Glamis and other dunes having this problem but it was usually after they crashed. Would removing the air baffles allow these sand particles to bypass the air filter? I'm running a UNI filter and oiled a couple of days before I went out so I dont think air filter quality/maintenance is the problem.

Should I take my bike into a mechanic and have them disassemble/ clean the carb? Or does the silt just settle into the bottom of the float bowl? :)

Im wondering if the junk got in thru your carb vent tubes?

Im wondering if the junk got in thru your carb vent tubes?

No, I'm tearing my bike down to clean it and there's about a pound of sand inside of the air box cavity. Even though the air filter was well oiled it looks like some of the silt got past the air filter. I never did put a grease seal around the backside of the air filter but I will now.

Does anyone know if I should have the carb taken apart and cleaned? :) I'm assuming I should.

Always grease the back of your filter! :)

Completely take the carb apart and clean it. Sand is the worst thing for your engine and carb. :)

Always grease the back of your filter! :)

Completely take the carb apart and clean it. Sand is the worst thing for your engine and carb. :p

Thanks Indy, every bike I've ever ridden I've greased the back of my filter except for this one. Stupid is as stupid does :)

also, be careful around the airbox if you use a coin operated car wash. i always pull the side cover and inspect the airbox after cleaning the bike. i use paper a couple of paper towels to dry up any water or sludge that finds its way inside, especially at the bottom.

Always grease the back of your filter! :)

Completely take the carb apart and clean it. Sand is the worst thing for your engine and carb. :)

Indy. What kind of grease? You're not talking the spray on oil for the filter are you? Something more heavy, like axel grease or such?

regular grease is to be placed on the filter contact area with the airbox

I ve just cleaned my carb completely, trying to fix low/high idle problem and occasional leakage

presume (not yet mounted) that the idle problem was dirt gathered inside the hot start knob (mounted near the carb (99 WR), so it didnt seal the air out 100%, now it does :)

dirt entered because the seal was not mounted properly

there are many ways for foreign object to enter your carb, better learn to clean it yourself, to save time and $$

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