400ex wont start

[mdt75crazy]

hey was hoping someone can help me figure out why she wont start. i bought it over the summer and its my first quad and dont know much about them. its a 2001 400ex with the 440 big bore kit and pro circuit pipe. factory airbox w/k+n filter.
i have no idea how it is jetted, i bought it this way. i took it to the local honda dealership after i got it to have it checked out and make sure it was in tip top shape and a ready for a season of riding.they were very impressed with the condition of it and how it ran.(it still has the factory tires on it!) they even boasted how easily it started then. seemed liked the colder it got outside, the harder it got to start. i gave her a good bath at the carwash around x-mas and barely got it started to drive it back into the shed when i got back home.it sat untill yesterday. it has been very cold here in indiana. it fired up a couple times but immediatly died and would not fire up again. i tried again today with warmer temps and wouldn't fire up at all and i ended up draining the battery. figured i would start with replacing the spark plug(who knows could be the original plug for all i know). it didnt have any fuel stablizer in it till i added it in today and then drained the carb bowl a couple times and still wouldn't fire up. my 91 250ex fired right up and so did my buddy's 400ex and neither had any fuel stablizer in them.
any help or suggestions would be greatly appreciated.

[rocky_mtn_honda]

clean your carb and fuel tank?

[mdt75crazy]

no... wouldn't even know where to start...

it never idled funny or cut out on me. i always check the tank before filling and it has always been spotless in there.i always keep premium gas in it.

but then again it never smelled like it was flooded when doing all that cranking over?

[chucked]

Is it the stock carb? Does it have a choke? Since you were at a car wash, possibly could have got water in the motor. Try changing the plug. Then pump the gas 3-5 times before cranking.

[steve181]

Originally posted by mdt75crazy
no... wouldn't even know where to start...

it never idled funny or cut out on me. i always check the tank before filling and it has always been spotless in there.i always keep premium gas in it.

but then again it never smelled like it was flooded when doing all that cranking over?

Cold makes gas gum up

with nothing added to the gas, it is most likely gumed up

[Which 450?]

Originally posted by steve181
Cold makes gas gum up

with nothing added to the gas, it is most likely gumed up

its hard to diag something over the internet. It hasnt been a month since it was last ran. Its not going to be completely gummed up yet. The first thing to gum up is the pilot jet. The first symptom of needing the carb cleaned is not idling. So how you begin to diag the problem is to pump the gas. This actuates the accelerator pump, pumping gas into the motor. Then if it tries to fire you know you have a fuel problem.

[bigbad400]

id get a bigger pilot and some new gas. try new gas first but more than likely in the cold youll need a bigger pilot. like 40 or 42 maybe 45 depending on your machine. good luck.

[johnnynonails]

did it run ok before you washed it ?,sounds to me like theres been water laying somewhere,carb,airbox/filter,take the carb off and give it a good clean.john

[bigbad400]

also it sounds like you may have a plugged screen in the bottom of the tank. it may not even be getting gas if it didnt sputter or anything. its in the petcock, you have to drain the gas, and take the petcock out and clean it real good, it wont matter how clean you keep it if its too cold, like stated gas gets gummy in the cold. i saw gas that looked like applesauce befor. :eek2:

[SWEENDOG]

Try changing the plug. The 400ex is real easy to fluid during the winter months, Instead of sitting there running down your battery have your buddy tow you down the road and bump start it. Just make sure when you get it started that you let it warm up or else you could cold seize the motor. Being its a 440, I sure it has a higher comp. Ratio then your buddys stock 400. We do this all the time before are ice races.

Good luck, Let me know if this helped

[mdt75crazy]

Originally posted by chucked
Is it the stock carb? Does it have a choke? Since you were at a car wash, possibly could have got water in the motor. Try changing the plug. Then pump the gas 3-5 times before cranking.

yeah it has stock carb and choke. was going to change the plug but the dang socket was too big. gonna get a thin walled socket tomorrow.

[mdt75crazy]

Originally posted by johnnynonails
did it run ok before you washed it ?,sounds to me like theres been water laying somewhere,carb,airbox/filter,take the carb off and give it a good clean.john

ran fine before i washed it and ran fine after when loading it back up.

[mdt75crazy]

Originally posted by bigbad400
also it sounds like you may have a plugged screen in the bottom of the tank. it may not even be getting gas if it didnt sputter or anything. its in the petcock, you have to drain the gas, and take the petcock out and clean it real good, it wont matter how clean you keep it if its too cold, like stated gas gets gummy in the cold. i saw gas that looked like applesauce befor. :eek2:

i'm getting gas to the carb. i drained the bowl a couple times.

[mdt75crazy]

YAY!!! she started and is running great!

re-charged my battery today,disconnected and reconnected the plug wire and pulled off the air box lid and she fired right up!

don't know what the deal was. maybe the battery was too low yesterday from over cranking it the day before and maybe it was jus too dang cold out for her? temps finally hit 40 today. are these things that cold natured?

Thanks for the input and your time guys.

[Rscarpantonio]

ive always herd taht people have trouble firing them up in the cold weather but i personally have never had that problem living in florida. glad you finally got it started