Maintenance on the 400 EX

[striker1001]

Hey guys Im new to this site and it seems to have alot of info and responses to it. Ive only been riding for 6 months and the 400 ex is one hell of a bike. Im not really knowledgable in mechanics either so i have some questions. I need to know how to adjust the chain on it. I loosen the 4 fixing bolts but I cant turn the adjuster. Is something wrong or do I just really need to put alot of strength in it. I know this might be a stupid question but where is the spark plug located and how do I replace it. Also when clening the air filter is it ok to clean it with gasoline. I have heard yes and no from diferent people. Please help.:)

[blackwell17]

jack up the rear of the quad and spin the axle as u turn the adjuster

spark plug is on top of the engine...i have to take off my gas tank to get to it. You'll see the yellow rubber spark plug boot and that leads right into the spark plug. You'll need a 18 mm thin walled deep socket to get it out.

as for the air filter, I have no idea on that.

[hawaiiansupaman]

you can leave the gas tank on and check your spark plug just use the tool that comes with the quad....as for the filter i wouldnt use gas its going to eat up the filter quick just use dish soap and water.. seems to work for me

[adrenalinefreak]

Welcome,

I haven't messed with the spark plug yet, but to adjust the chain I did what the person above said and worked like a charm...

As for the air filter, I've heard it depends on the type of filter you have...I have the K&N Air filter and I use K&N Air filter cleaner and then apply the oil and then put the outwear on...

When I had the foam kind of air filter I would use the same stuff, but I've heard you can use a product called simple green because it is harmless on the filter itself...

[trx400exxracer]

the proper way to clean a foam air filter is to

squeeze in kerosene ( it is better for ceanig atv parts)

then wash it with soap and water and squeeze it and make sure no soap is in the filter

and then let it dry

and when it is completely dry you can spray or rub in the air filter oil


:D :D :D :D :D :D :D :D

[striker1001]

The chain adjuster wont move. Do I need to do something or is something wrong with it:confused:

how are you trying to turn it? I used a hammar and punch to turn mine once.


for the filter,, I can tell you that you shouldent use paint thinner.. lol. I just dunked my uni in a bucket of thinner and it expaned 1/2 again its size, I washed it off quick and it appers to be fine. But it is all flimsy.

[striker1001]

i tried using an allen wrench and screwdriver to turn the adjuster. I havent adjusted the chain since I first got it. Could it be something wrong with it inside. Or do i just need more strngth.:confused:

[blackwell17]

mine takes hardly any strength at all:huh

as I recal my stock carrier took a good wack with a hammar and punch to turn it. I dont see how you can hurt anything by hammaring on it. so let-er-rip

oh and sometimes weging the swing arm open on the back with a little chisle helps.

[400EXtreme]

Originally posted by hawaiiansupaman
you can leave the gas tank on and check your spark plug just use the tool that comes with the quad....as for the filter i wouldnt use gas its going to eat up the filter quick just use dish soap and water.. seems to work for me thats the worse way to clean an air filter. Make sure you dont use a blow dyer that will shrink it.

gas wont eat a filter. plenty of gas gets sprayed onto the filter durring use.

[Rip_Tear]

Originally posted by mittimj
gas wont eat a filter. plenty of gas gets sprayed onto the filter durring use.

Gas is no worse then kerosene, but I'd just use warm water and dish soap...

Provided you have the stock tools and you haven't said anything more about it, I assume you are okay with the spark plug.

Doing your chain adjustment should be really easy, it sounds like you could do with spraying some WD-40 at the carrier where the slit in the swing arm is (those 4 allen bolts). You can try using a punch and hammer if you want on the adjuster slots (you may damage them). If you use a soft metal like aluminum, or a hard plastic as the punch you'll less likely damage the adjuster.

[striker1001]

Thanks guys i finally adjusted my chain. The water and soap idea didn't work so great but I managed, I guess Ill kepp using gas. :)Oh and for the spark plug how the hell do u get to it. Do u really need to remove the gas tank. If so, how.(Step by step would be real awesome):)

[DaleJrFan]

Welcome to the site. The first time I adjusted my chain the bolts were pretty tight but now I have done it several times for various reasons, they are pretty easy now. As for the filter, if it is the stock filter, I wouldn't go overboard with the gas but it would work, even if you dont have a K&N filter, you can buy their cleaning kit and use it on the stock filter. The 400 is unique as for the spark plug, you have to have a Honda made spark plug wrench or grind down a old 17mm to get to it. To remove the gas tank isnt that hard, you just have to remove the plastics, unscrew the ignition and pop off all the plastic holders around the front piece and lay it to one side, the tank is just held on by straps.

The single greatest thing you can invest in right now is a Clymer repair manual. They are very detailed if you are not very maintenance inclined. You can PM me if you have any questions about other stuff, I check this daily.

Again welcome, Steve

the tank is held on with 2 straps AND 2 bolts up neer the steering stem. I think they have a 8mm head on them.

[coryatver]

You don't need to remove anything to get to the spark plug. Just use the wrench in the tool kit.

[blackwell17]

yea well not everyone got a toolkit with their ex's...some of us bought them used without the toolkits :rolleyes:

and its a 18mm socket, not 17

[trx400exxracer]

Originally posted by striker1001
Thanks guys i finally adjusted my chain. The water and soap idea didn't work so great but I managed, I guess Ill kepp using gas. :)Oh and for the spark plug how the hell do u get to it. Do u really need to remove the gas tank. If so, how.(Step by step would be real awesome):)

what about my method of cleaning air filters:confused:

it gets the job done no matter what

[guinness77]

Adjusting the chain, cleaning the air filter,changing the oiland oil filter are essential and basic. Every 100 hours (or so) adjust your valves. It's easier than you might think.

[dirteater74]

For the chain adjuster I use a spanner wrench for adjusting shock preload, it fits the chain adjuster perfect.

[inthsaddle]

look under the tech articles page for info on your oil change and valve adjustment's