Hi,
I have a bone stock 1999 400EX. It is 0 degrees Farenheight outside right now. My EX has been sitting for 12 days in frigid weather. I am going outside right now and I am going to start it.

Here is my prediction:
It will start within 3 seconds because I will full choke it then pump the accelerator about 5 times. It will probably die almost immediately, but, I will pump it again and it will fire up. Then I will be able to keep it running by teasing the throttle. I will have to keep full choke on for about 30 seconds to 1 minute, then go to half-choke for about 3-5 minutes.

Will my prediction come true?... Back in 10 minutes...

(oh the suspense, I am sure!...)

phil

 

Ok, my prediction was significantly off.

I pumped the throttle 5 times. Pressed the starter for 4 or 5 seconds. It was barely turning over. I pumped it 5 more times and tried the starter again for 4 or 5 seconds. Still no start, not even a pop. I tried the starter again for about 6 or seven seconds and when I was about to let off, it started. It stayed running and all I did was hold the throttle open a little so it would idle fast. I didn't pump or tease it. I let it run full choke for about a minute, then when I switched to half choke, it died. I pumped the throttle 3 times and left it on half-choke. It started and stayed running, and continued running when I switched the choke off about 3 minutes later.

I am still running the original spark plug, and I have never fouled it.
I got the quad in september 1998.

Anyway, I am a believer in the throttle pump theory for cold weather starting. I hope this little outburst helps prove a point. I also hope it will convert you all to the throttle pump theory too. :-)

Good luck 400EX'ers,
phil

PS: my quad has been sitting because I haven't the kahunas anymore for riding in the frost. (i.e. : wimpy)

 

The thrttle pump theory has proven to be effective on my 300 ex and my cold natured 81 cb750 custom.You guys with the 400 exs should give the thumb throttle a few pushes before hitting the starter.It should work but don't get carried away with it.Also remember the manual says to take the machine off full choke as soon as possible,even if you have to nurse the throttle some to keep it running.
s scott

 

Thanks for the tip balzie33.
My first quad was a Yamaha Blaster. It was a great quad. It still is a great quad, but it has sure been through hell and back. I still have the original paperwork from when I bought it brand new in 1988 (yep, I am one of those types) Total cost with tax and delivery, brand new, was $2048!
Yes, I rode it all winter. Very much more than I ride now. It always started great, no matter how cold it was. I don't ever remember fouling a plug on that quad either. I never would hesitate to come home from work at about 11:30 at night, start the Blaster and ride about 7 miles to my friends house for Nintendo. Zero, minus 10, it didn't matter.
It only let me down once. I was alone, about 5 miles out in the woods and 4th gear broke. Locked it up tighter than tight. I somehow pried the chain off and started pushing it home. Luckily it wasn't too far to a road, and it was hunting season. A couple guys with pickup hauled me and the quad home. When I tore it down, I discovered 3rd 4th and 5th were all broken. Weird.

Anyway, sorry I couldn't get into the my quad is better than yours mode.
I was just trying to help with my reply.

phil

 

Phil, I'll try your method. It sounds like it would work.

Locos, my 250R is a performance machine and it starts with in the 5th kick, normally 3rd and its 12 years old!

Balie33, I guess I'm just another dumb idiot that doesn't know a thing about ATVs.

Blaster85, I plan to buy a Banhsee in a few months. If I wanted pure speed, I would have got it first, but I didn't. Maybe next time you'll think and respect other people and their decisions.

BTW- I owned a Blaster(1998) and then I sold it and got a 400EX. Great quad but I'm getting to good and old for it. My number 1 choice for starter quad.

Happy Trails



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Evan Johnson 400EX/LT250R

 

Throttle pump works great on my 400EX. I do the same thing as wvblaster, scotster750 and philzie. I even use throttle pumping in the summer because I ride on the weekends and it sits in the garage all week long.

 

I have a 300ex and i live up in nothern Canada I have never ever ever had a problem getting it started and i think it is one of THE BEST SPORT MACHINES AROUND
the 400ex is a High performance machine and is ment more for warm weather but the guys with the banshee and the ****ty blaster say oo they start so good i used to have a banshee untill i got sick of fixing it and almost put a Heat kit on the grab bar so that your hands wouldn't get cold when u where pushing it into the shop!!! HEHEHEthen i bought a Honda and although it isn't as fast I sure love the relibilty I have a bunch of mods and it runs GREAT

I will never have to buy another quad as long as i live

RIDE RED OR GO HOME

DG_300EX
98 300EX

 

Well, me an pa went ouit to the car hole or should I say quad hole? But anyway, we came to the conclusion that the batery was dead. We charges it up and what do ya know, it works! Since it had been sitting in the freezing cold for about a month, the battery died. He said its common so I didn't worry.

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Evan Johnson 400EX/LT250R

 

yo DG_300ex I to live in Cold Temp. & let me tell you have 1 chance to start the 400ex because if you don't you gotta clean the plug & charge the battery to try 1 more time. By the way when its -15 outside and you pump that 400, You flood it so fast.

 

If you have a turbo heater point that at the engine for a few minutes. Seriously...

A Honda not starting in the cold weather??? That's the nature of the beast.
c-ya,

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Andrew Thomas

'99 Scrambler 400 & '99 Trailblazer, both with RCR mods.