These machines are hard to start when its cold. I'm here in NY and its been 30's during the day and teens at night. I just had a problem yesterday and I flooded it!! This is what I did, I got a salamander and let it sit there for about 10-15 mins and I changed the spark plug because I flooded it and BANG!!! It started!! Probably until winter ends that is what I'll do. I know it's kinda weird to do all that but, hey! it works

Mine starts easy /when was stock jetted also/now I run 2 sizes bigger pilot jet an it's even better,went up 2 on the main also ,but that has nothing to do for starting.I live in northern Nevada an it does get cold here too,just try a few different pilot jets it might help.

I live in NJ. I always have trouble getting it started. TOday i had to charge the battery. But usually it just flouds and i change plugs. I just by 3 or so and keep re-using them and cleaning them for awhile. It works.

Thats one bad design on the 400ex.First is the bad location on the carb for the choke.Second and most important is when the choke is on it doesnt kick the idle up when cold.I could never figure out why honda does that.Im happy now that the raptor choke is on the handlebars and it also kicks theidle up when on.Just goes to show you that all the manufactures have their ups and downs.I used to start my 400ex then use a wire to hold the thumb throttle open at a high idle till it warmed up.What a pain in the ass that was though.

I guess where back in nursery school again!! right x250rdude???????

just bought a 2000 400EX today. i heard they are very cold natured and it was about 30 today. it took the guy 15 minutes to start when i bought it, and when i got it home i tried for about 10 minutes before the battery gave out. is this normal? is there any fix for this, and will my batter charge back up any after i finally get it started? thanks

Hi,
I just bought a 2001 400 ex and have had to charge the battery once already myself. i live in NY myself and let me tell you I can't take it when it takes forever to start. I can't wait for the summer. It was hard for me to comprehend how something so new can't start.

Joe

A simple solution is to go to a 42 pilot jet. This is a very easy solution and has made cold starts much easier in the cold New England weather. I had one heck of a time with the stock 38 pilot jet last winter, but it seems as if the 42 is perfect for my machine. I also raise the idle speed until the machine warms up, which is a simple finger turn of the idle screw. Once warmed, I just back it off to the normal idle speed. Hope this helps..

Another simple solution is to richen the fuel/air mixture screw located under the carb, right in front of the float bowl. Just turn it out 1/2 to a full turn, see how it starts then.

ogre