I bought a 2005 Honda 400ex and the guy said he ran it and never checked the oil or somthing and one day it just stoped running on him because it ran out of oil . It sounds to me like it does not have compersion so before I take it apart and order parts is there anyone who might know right off the back what all will need to be replaced to get this running again. And if it needs a new piston or needs to be re sleved should I get a big bore kit? Im new to Quads so im not too sure what all upgrades is worth doing. But mainly I just wanna get this running.

 

for the money you can pick up a 400EX motor used. I got one couple years ago for 300 bucks.

 

typically when a motor is oil starved the crank bears go out and the rod bearings weld themselves together.
i've got a wall of cranks at my shop that you CAN NOT ******* move the rods.. lmao.

depends on how bad all that shti is tho. "normally" a few bearings will get trashed.. the rings usually survive because the crank locks before the walls get scored.

not always.

do a comp test (dry) then do a wet test. like 1 or 2 capfuls of oil or ATF. if the compression comes up DRASTICALLY (if the motor spins at all) between the wet and dry test, replace the rings and re-hone the bore. inspect bore taper and determine whether to bore it or just to resurface it with a ball hone to crosshatch it and break the glaze.

if the motor DOES turn over and you don't not a pressure increase from dry to wet above 50% of the dry value, then don't worry about the rings.


i have rebuild motos where i have only replaced the crank bearings and ones where EVERY single ******* bearing and seal was shot, and it took like 3 hours to clear out the piles (literally) of metal shavings and clean the cases. i have pics of that ****..lol it was ******* amazing.



inspect the oil pump as well. if the rotor is pitted or the housing is all scratched up, replace it. they don't run much pressure.
i have an 400EX in my shop right now and a manual.. i'll look up the oil pressure spoecs if you need them.

i mean, theres alot of **** to a rebuild. i'll gladly walk ya thru or if you ever feel like makin a road trip up to martinsburg wv, i'll rebuild that bitch for ya

 

how much would you charge haha?

 

depends on the damage!!

the shop fee is 55 an hour, which is actually pretty cheap.. at least around here.. and it'll probably be anywhere from 3-6 hours.. more towards 5 or so if the ***** in the frame still and i gotta rip the motor out.

honestly, i'd probably personally do that at my house instead for a multitude of reasons.. A. it's a cleaner and more organized environment with less **** going on, B. no CHANCE of anything getting mixed up or assembled incorrectly cuz of doing a million other things in the middle of a build, C. i only make $10 an hour at that shop

haha..



i mean, if you've got some mechanical inclination, you can pull it off.. you might want a manual just for torque specs n **** like that.. just did an RM 250 where i only replaced the crank and main bearings.. reused everything else including the cylinder.
the thing was so new i didn't even have to crosshatch the bore... there was still factory marks in it!!


anyway.. i'll gladly walk ya thru it if you want. aint no thing. splitting the case and reassembling without killing gears and gaskets is the biggest bitch.

then again, i guess you pay for the builder's knowledge when you take something to a shop.. i already have the tools and a few tricks i've developed over time to facilitate better assembly with less trouble!!

 

yea I think ill give it a shot, ill give ya a PM if I need some helps thanks alot