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TakinItEasy
12-17-2005, 09:25 PM
hey guys i was just wondering if u all have any trouble starting yur 4 wheelers in cold weather. i cant get mine to start for nothin in cold weather. i gotta push it and pop the clutch to actually get it runnin. but anyways just wondering if all or most 4 wheelers are like this. thanks
h400exrydr
12-17-2005, 09:30 PM
do u have a rev box in it? if u do that is probably it, other wise to start it wit the choke put the choke all the way up and then when it fires hold the throttle a lil bit so it is above idle
TakinItEasy
12-17-2005, 11:50 PM
im not for sure if its got a rev box or not. i bought it used last spring. as far as performance all its got is a k&n filter in it. i have the choke all the way up and it dont do **** but wear the battery down. need help. if when it was warm, it took a while to get to stay running.
h400exrydr
12-17-2005, 11:55 PM
then it probably has a rev box, try and put the quad in a heated garage that is like 65 degrees and then it should start. if it starts then it probably does have a box.
tprender
12-18-2005, 06:01 AM
You might want to go one size larger on the pilot jet. Change to the stock CDI for cold weather if it does have a different one. You will find that all of the 4-stokes are hard to start in the cold weather.
quad2xtreme
12-18-2005, 06:55 AM
Originally posted by TakinItEasy
hey guys i was just wondering if u all have any trouble starting yur 4 wheelers in cold weather. i cant get mine to start for nothin in cold weather. i gotta push it and pop the clutch to actually get it runnin. but anyways just wondering if all or most 4 wheelers are like this. thanks

Try this first,

pump the gas twice and then try to start with the choke fully on.

If it doesn't start,

install a Dynojet kit.

I have 3 400exs and all of them start with no problem all the way down to when it is about 10 degrees outside. My buddy kept his stock 400ex in my garage and it was a PITA to start. Like tprender says, it is all a matter of getting the pilot jet setup right. I find the Dynojet kit the easiest way to handle this. Also switch back to a stock CDI or at least keep your battery fully charged with a BatteryTender.



/Jon
400EXtreme
12-18-2005, 08:20 AM
It is probably your cdi. Cuz i have a stock 400ex with just a uni on it nd its fires rite up in cold weather.
atvracer980
12-18-2005, 08:25 AM
I'd go up 1-2 sizes with the pilot jet- its not a cdi issue- the 400ex has and needs the cdi. The 400ex's are just cold-blooded and need the extra fuel on initial starting- change the pilot jet.
ImWhite
12-18-2005, 08:44 AM
i have an aftermarket cdi on my 400 and it still starts in very cold weather....id do something with the pilot jet
TakinItEasy
12-18-2005, 11:26 AM
ok thanks for the responses. so what does cdi stand for? and what size pilot jet should i get? im such a noob with 4 wheelers. is getting a different size jet gonna or a cdi? gonna make my quad runnin better or worse when it comes to summer?
h400exrydr
12-18-2005, 12:14 PM
42 pilot jet makes mine fire up really easy and i dont have a choke...all u gota do is hit the throttle like 2 times and itll fire.
atvracer980
12-18-2005, 01:02 PM
I've got a 50 or 52 pilot jet w/ the choke mod, and it doesnt effect it in the summer.
TakinItEasy
12-18-2005, 01:07 PM
so how big is the stock jet and what size jet do u guys recommend for just a k&n air filter as the only performance mod?
tprender
12-18-2005, 04:28 PM
Stock size is 38. Go to a 42 if you still have a stock engine. Anything bigger than than with stock is a waste of gas.
ENASNI TILLER
12-18-2005, 05:09 PM
Mine will not start in cold weather for nothing. Its been sitting in garage since I bought it lol. Maybe I need to try the pilot jet thing.
acw592
12-18-2005, 08:27 PM
Like the others said, a 42 pilot jet....I removed my choke and installed the 42 pilot, mine starts fine.
Rico
12-19-2005, 07:19 AM
Leave the POS choke alone. Worst feature of the 400ex I think.
ride red 14
12-21-2005, 09:16 AM
Originally posted by TakinItEasy
hey guys i was just wondering if u all have any trouble starting yur 4 wheelers in cold weather. i cant get mine to start for nothin in cold weather. i gotta push it and pop the clutch to actually get it runnin. but anyways just wondering if all or most 4 wheelers are like this. thanks

my 400ex is so coled natured it gets so flooded that gass flows out the exaust
ENASNI TILLER
12-21-2005, 07:02 PM
Originally posted by Rico
Leave the POS choke alone. Worst feature of the 400ex I think.

So you dont even use the choke?
GOTFEAR
12-21-2005, 11:56 PM
I would look at my valve clearnc 4 on IN and 5 on the EX
Pappy
12-21-2005, 11:58 PM
Originally posted by Rico
Leave the POS choke alone. Worst feature of the 400ex I think.

amen, 3 stabs of the throttle and hit the go button!
Rico
12-22-2005, 05:39 AM
Originally posted by ENASNI TILLER
So you dont even use the choke?

I took the mutha chucker out about 4 years ago. If you like fouling plugs then the choke is your best friend.

As pappy stated, hit the throttle 3 times then the starter, do this a few times and she'll finally turn over.
quad2xtreme
12-22-2005, 07:04 AM
Originally posted by Rico
I took the mutha chucker out about 4 years ago. If you like fouling plugs then the choke is your best friend.

As pappy stated, hit the throttle 3 times then the starter, do this a few times and she'll finally turn over.

I guess I've been lucky since I've never fouled a plug but I really attribute it to the Dynojet needle. Same when I had the Raptor. Had friends all trying to rejet using factory jets and could never get it completely right across the entire range. I installed a Dynojet kit on the Raptor and never had any problems from idling to full throttle. I never understood all the fuss about rejetting. Same with the 400ex. I had to change the plug once in the spare quad when I let it sit a few months without starting it but that was it.

I am a firm believer in the Dynojet kits for anyone with a stock 400ex even if you don't install an aftermarket exhaust.

/Jon
Rico
12-22-2005, 08:13 AM
Originally posted by quad2xtreme
I guess I've been lucky since I've never fouled a plug but I really attribute it to the Dynojet needle. Same when I had the Raptor. Had friends all trying to rejet using factory jets and could never get it completely right across the entire range. I installed a Dynojet kit on the Raptor and never had any problems from idling to full throttle. I never understood all the fuss about rejetting. Same with the 400ex. I had to change the plug once in the spare quad when I let it sit a few months without starting it but that was it.

I am a firm believer in the Dynojet kits for anyone with a stock 400ex even if you don't install an aftermarket exhaust.

/Jon

I also run a dynojet kit and have since the beginning.