Ok, it's been 4 months since I picked up my 2000 400EX and for the most part I've very happy with it. It was originally acquired so that I might give up motocross racing, since I seem to be fairly injury prone in that activity. Don't think I can give up racing bikes just yet, but I'll keep the EX for trails. It's a great machine, but there are a few items I'm not thrilled about.

First, the spark plug access. I'm using a deep socket so maybe a specific plug wrench would help. It's pretty difficult to remove/install.

Second, I'm hearing that these things are usually cold runners; much like all Honda equipment(I have a CR250). I can't seem to get mine to fire in cold weather without first shooting alittle starting fluid in the air cleaner. I've seen some threads on this in the forum. What are people using for fuel? Any additives?

Lastly, what's the deal with the seat? Is there a trick to removal and installation? They could have better designed the fins on the front.

Maybe I just don't have enough experience with this machine, so I'd appreciate some feedback.
Thanks...
dmichael.

 

Use the factory plug wrench (or even better, use an XR400 wrench) to remove the plug.

Really the reason they are cold blooded is that they are jetted lean, especially on the pilot side, from the factory to make the greenies happy. Correct this and it should start pretty easily. Also, if you have a WB or XR250 CDI - they need to turn a higher RPM than a 400EX CDI to initiate a strong spark. If your bike is turning over even the least bit slow, it will not fire with one of these CDIs. I have never had any trouble starting mine, even in near 0 deg F conditions with correct jetting and the stock CDI (really the only problems I have had was with my XR250 CDI).

The seat is not that bad, removal is easy, but theres a little technique involved for easy reinstallation. Just make sure to kinda **** it sideways over the battery first, then hook the front on the gas-tank stud, they should then slide on pretty easily. A little practice will make this an easy task.

 

Gabe, Do you have aftermarket shocks on your 400 in the photos with the BIG air? I love to jump and am still learning but just wonder if a stock quad can get that much air. Angelon400ex

 

The seat thing will come with time!!!! I still cuss when putting mine on.
My husband had the WB rev box on his 440ex and it wouldn't start in this cold weather...once he put the stock rev box back on it fired right up!!!
86atc250r...are you talking about the Motion Pro socket???? That socket works wonders on the EX plugs!!!! It's well worth the purchase for you other 400ex owners!!! Takes a lot of the hassle out of changing the plugs.

 

I have been running 87 octane fuel in my 400ex, and just today, i started using 92. I starts better and seems to have more snap. Also, Before starting, pump the throttle 3-6 times and then start it(using full choke). It made a bit of difference for me.