2002 400ex problem

[catchmeifucan]

i just bought a 2002 400ex...it got a k&n and the guy guy i boughtit from gutted the stock pipe....i was rflyin down the road and dropped 2 gears and gunned it and got sideways around a corner ...when i shifted up and hit the throottel it died and the wheels locked up almost causin me to fly off...now it wont start...it wont even turn over.....all it does is the starter silinoid clicks and the starter whines a little...im thinkin maybe the motor locked up but its kinda hard to beleive considering its age....can anyone give me some insite or suggestions an what they think it might be....if it is locked up what bore kit is recominded...and also the jet kit and full exhaust is recomended....any help is is greatly appreciated......thanx

[Steve-o 400EX]

Try and turn it over by hand if it can be done. I would get if checked by a mechanic if it wont budge. Did it have oil in it?? My friends 300ex did that when he did not have any oil in it, the rear tires locked up and didnt move.

If you need a bore kit, go with a 416 10.8:1 compression, hotcam stage 2 and a promeg exhaust.

let me know what happend when u find out.

[catchmeifucan]

the bike was a little low but there was for surely oil in it ....i dont get it...when i got the bike the plug was fowled out cuz the guy had been puttin around on it..honda told me the motor is almost bullet proof.....so when im ridin to tear into it as much as possible to keep the plug from fowlin out..so i did....as far as a pipe what does everyon think about the ct racing or the white bros.e-series....ive only had this thing a few days and then this happens...i know the guy really well and i know he wouldnt intentionally give me a bunk quad.....he also has had this thing out at the local tracks in the houston area..so i know its been rann a little hard but still i think its to new to go out already.....

[K_Fulk]

The ct pipe is a good pipe but it sticks out past the grabbar some. The e-series ct and dmc are probly 3 of the best pipes for stock motors.

To turn the motor over manually take a allen wrench and take off the middle cover on the side case on the clutch lever side then use the allan wrench to see if you can turn the motor over

Even if you have it in neutral it won't roll????

do like Kfulk said,,he beat me to it..if it rolls in neutral you got other issues..:(

[catchmeifucan]

the bike rolls in neutral but when i put it in gear it locks up.....only reason i thought of the motor lockin up is cuz the flywheel wont turn with the starter

[Extremeracer167]

Originally posted by catchmeifucan
i was rflyin down the road and dropped 2 gears and gunned it

If u do that to any motor its liable to blow. When u are riding a quad, its not meant to be FLYING down the road and then dropped 2 gears then gunned again.:rolleyes:

[catchmeifucan]

i didnt mean like dropped 2 gears to take off...i was slowin down already as it is...

[TheX1992]

same thing hapened to me on my 250x! only the tranny gears splined and locked up. what you do is remove the nut on the left side of the case (bigger one in the middle). this gives you access to the crankshaft nut. take a 11/16 long socket (i believe) and extension and ratchet and turn the bolt clockwise and see if the piston moves. once i unlocked the gears on mine it ran perfect. if it wont turn right, turn it left but not to hard because the bolt will losen . give it a try before you rip apart your head

[catchmeifucan]

thanx for all the info guys i reall do appreciate it...im gonna give everything yall have suggested and see what happens hopefully it works for mine and my wallets sake

[Extremeracer167]

lol my bad. Actually when u take that cap off, i think u turn it with a 17mm sicket, not an allen wrench. ;)

[K_Fulk]

Originally posted by Extremeracer167
lol my bad. Actually when u take that cap off, i think u turn it with a 17mm sicket, not an allen wrench. ;)

Yeah it is a 17mm i was thinking it used a allen wrench too but its been awhile.

Originally posted by Extremeracer167
lol my bad. Actually when u take that cap off, i think u turn it with a 17mm sicket, not an allen wrench. ;)

And turn it COUNTER CLOCKWISE..;)

[Extremeracer167]

and while your at it, ide check your timing as well. If u know how to do it. if not ide get a service manual, those things are lifesavers!

[catchmeifucan]

where can i get a service manual for it at

[Steve-o 400EX]

Originally posted by catchmeifucan
where can i get a service manual for it at

Usually you can get em from you local dealer. If not search online for a CLYMER MANUAL FOR A 400EX.

Also i got a WB pipe and love it. It gave me pretty good gains.

[Extremeracer167]

Get a HONDA SERVICE MANUAL!! they are more $$ but worth it.

[trxex]

sorry to hear that.that should not have happened.this is just a guess but you stated the oil was a bit low.it is possible when you made the turn and punched the throttle being your oil was low and possibly dirty you might have sucked air into your oil pump (being a dry sump)and sezied you motor.the very first thing anyone should do when buying a used quad is change the oil and filter!you dont realy know how long the oil has been used or what grade it is ,also the old owner might have never changed the oil filter witch would restrict the flow.this is just a possible guess what went wrong. :confused:

[catchmeifucan]

well guys thanx for all the info and help but i have bad news...i tore down the engine and foundthat the rod snapped in half and busted off a big chunck of the sleeve...also took out a big peice of the right side of the crank case.....now my question is where do i go from here....can i just replace that side of the crank case or do i need the whole thing...and if anyone has any parts lyin around let me know cuz im gonna need them im sure.....honda wants 300 per side for the case so if anyone has a case and is will ing to ship it to houston which il be more than willin to pay the shippin i need to get my quad runnin asap so i need the parts very soon.....any help will be greatly appreciated...thanx again....