'01 400 won't start. Please help.

[2001400ex]

Hey, I need some help with troubleshooting on my 400. It won't start, the last time I went riding I fouled my plug and rode it home and just threw it in the garage without changing or cleaning the plug. (I know this is not good and I never ever do this, but I was having a bad day and didn't feel like wrestling with my quad to get the plug.) So, today I finally got the chance to clean off my plug. It was preety black but wasn't soaked with gas, although it did smell like gas. I cleaned it off very good so that I could not see any black anywhere on the plug with some sandpaper and put it back in....it still won't start.

When I took off my back plastics I checked my airbox to see if it had gas or water in it and there wasn't anything in there. My little resivour at the bottom was filled with water, but I think that could just be from riding in the snow.

I have a HMF slip on. I'm running a 42 pilot jet. 165 mian jet, my lid is on, and I belive I'm at 3-1/2 turns out on my air-fuel screw. I'll double check after I'm done posting this. Right now the temperature is 37* out - which I don't think is too warm for a 42 pilot. I would really like to get it started because I haven't ridden in about two or three weeks and I'm getting antsy. Please help. Thanks in advance.

(I'm going to check my air-fuel screw right now and I'll re-post what I'm at.)

[2001400ex]

I was at 2 turns. Any help would be appreciated.

[Fortman_400]

hey i had the same problem that i just fixed today.
a couple of weeks ago my sisters fiance' rode my '99 400ex on choke for an hour and fould the plug terribly,, that moron didn't know how to ride, lol. but today i replaced the plug and it still wouldn't start,, so what i did was take off the air box and air filter,, spray in some starting fluid, and it should start then. if it doesn't start with starting fluid, then ur not gettin a spark and its a fuel line problem. but once u get it started with ether or starting fluid, keep it running cuz mine i had to keep it at about 3000 rpm (guessing) because it kept missing until i got the engine nice and hot again, then it would run perfectly. i let it down to idle and it just ran perfect.

[2001400ex]

Thanks I'm going to put my carb back on and everything because I noticed that I had alot of fuel inside my carb. I'll use the starting fluid too, don't let him ride your quad again either!:p

[Fortman_400]

only use the starting fluid if u can't get it to hit at all turnin the engine over normally or with choke on. starting fluid is just a last resort kind of thing because its about 4 or 5 times more combustable than gasoline and can blow head-gaskets if u use tooo much of it. i've seen it happen to snowmobiles before.

[2001400ex]

Alright thanks for that info, I haven't tried starting fluid yet, and the damn thing still won't start. I am running out of ideas, I'm going to try one more time, if it still won't start I'm going to see if I'm getting spark, after that I don't know what to do.:(

[2001400ex]

I just checked my spark and it's not really that great, is it possible to burn out a plug somehow? It doens't get constant spark, it wil sort of skip with the spark, it's very erratic. I'm going to try my old plug, hopefully that will help...:confused:

Update: I got it to start, somehow I think my other plug got blown because I put in my old plug and it fired right up, shot a flame just once but I'm not worried about that right now. Thanks for your help!;)

[Aceman]

You might of sanded the spark plug electrode down to much and opened the gap wider than it should of been. Resulting in poor spark.

[2001400ex]

I think that I sanded it down too much, I did also notice that the gap was bigger then my old plug, so I just tossed my new plug since it was shot and it fires right up now.;)