Cold starting 2003 400ex

[btheld]

I have a 2003 400ex I bought last fall. The machine has very few hours on it - completely stock everything (including pipe and air filter). It runs great, except that it fouls plugs when starting it cold. It does this if it is 10 degrees out or if it is 70 degrees.

So far, the best procedure for starting is using the choke, but not touching the throttle until the machine has fired and is running. Then use the throttle to keep it running - once it warms up, starting is much easier.

When it fouls the plug - it's completely black. I'm using the stock NGK plugs...

Any ideas on how to fix this?

[TheFontMaster]

Sounds like your getting too much gas in there at the initial start up. I would clean your carb, something might be dirty, alowing too much fuel to go into the cylinder. An while you have it apart just mark down what size jets are in there. If cleaning it doesn't work I would sugest going down a couple steps on the pilot jet, and posibley turning in the air/fuel screw a little bit.

[btheld]

I forgot to mention that the carb was recently disassembled and cleaned - no difference in behavior at all...

[ohsobad_chevy]

Originally posted by btheld
I forgot to mention that the carb was recently disassembled and cleaned - no difference in behavior at all...

If temperature is above 80, do not use the choke, puch the throttle in all the way, quickly, and then let go. Barely open the throttle and hit the starter. Should fire right up. Do not blip the throttle during warm up just barely keep it open.

[jsmith2232]

My personal experience is that most 400ex's are cold starting, the easiest way I found that helped out is to put in a 42 pilot and leave the choke off. Snap the throttle 3 times, if you slowly push it in the accelerator won't shoot gas into the cylinder so you have to push it fast and start it. I took the choke out of my stock carb and did that and it worked awesome.

[ohsobad_chevy]

Originally posted by jsmith2232
My personal experience is that most 400ex's are cold starting, the easiest way I found that helped out is to put in a 42 pilot and leave the choke off. Snap the throttle 3 times, if you slowly push it in the accelerator won't shoot gas into the cylinder so you have to push it fast and start it. I took the choke out of my stock carb and did that and it worked awesome.

Yup, 400ex's are hard starting if you don't ride the often. I get to ride about every 2 weeks, even then it is hard to start. Just how they are...:cool:

[idontknowwhoiam]

My choke doesnt work(dunno why just never did) but when i start my bike i turn my idle up prolly a full turn..and let it run idleing real high for a while then turn it back down b4 i ride and it works out for me