piston failure :)

[buck440]

im so happy i found this picture on my old computer, this was when i was a noob to riding and never thought to check the oil, i wish i had a picture of the bottom cause you can see where the valves were jamned into the piston.

[elmer91]

:eek2: :eek2: :eek2: :eek2: wow. i have seen quite a few bad pistons, but i think this one takes the cake.

[rob_990]

omg thats f'ed up

[cam19aro86]

Wow...I am in shock.

[Speedy 400ex]

:eek2: :eek2: :eek2: :eek2: I am never going to forget to check my oil from now on!!

[Exrider434]

you think thats bad???

[buck440]

Originally posted by Exrider434
you think thats bad??? holy crap :eek:

[Exrider434]

thats what 5th pinned and no oil on a hot summer day will do to ya haha, it totally screwed the entire motor though, bent the rod, bent all 4 valves snapped the cam chain, craked the piston sleeve and there was metal ground into all the gears in the bottom end, it was pretty bad.

[cam19aro86]

So, how is the rebuild going?

[buck440]

same here man, i was in fifth on a gravel road trying to keep up with my buddys kx250f and then a huge poof of smoke and flame and there i was, always always always check your oil, my bill was 1700 with a 250 discount, what was yours? oh yah it fixed already

[ae13291]

speaking of checking oil, i know since the 400ex is a dry sump, are you supposed to check the oil after warming up the motor for 3 minutes or do u check it cold?

[Exrider434]

Originally posted by cam19aro86
So, how is the rebuild going?

me? that was a good 4 or 5 years ago, that motors long gone. I got a whole new quad now, and the rebuild i got goin now is goin real slow.

[hypersnyper6947]

Yep i did that too, except i was only going about 10 mph, still managed to destroy the piston sleeve 2 valves and the whole lower end b/c the sleeve dropped a bunch of metal all into the lower. I bought my new motor from zrpilot cost me $950 but it has revers and puts down 37 hp i have the dyno sheets.

[buck440]

yah i wanted to put a yz426 or a ktm motor in it cause it would of been cheeper and faster but my dad said no :grr: and since he was paying for it he wanted derrrr gEnUIne HonDa PARtS, so now i think every thing in the motor is a little over a year old now, and i dont know about everybody else but i check my oil when its cold

[rob_990]

yea me to

[NacsMXer]

Originally posted by ae13291
speaking of checking oil, i know since the 400ex is a dry sump, are you supposed to check the oil after warming up the motor for 3 minutes or do u check it cold?

Never check the oil cold, nothing will show up on the dipstick.

As per the manual you should:

Place the quad on a level surface and let idle (don't touch the throttle) for 5 minutes. Turn off the motor, remove the dipstick and replace without screwing it in. Take note of oil level, drain or fill as necessary.

[buck440]

pssssssshhhhhh :rolleyes:

[ae13291]

Originally posted by NacsMXer
Never check the oil cold, nothing will show up on the dipstick.

As per the manual you should:

Place the quad on a level surface and let idle (don't touch the throttle) for 5 minutes. Turn off the motor, remove the dipstick and replace without screwing it in. Take note of oil level, drain or fill as necessary.

thank you very much for clarifying that for me buddy

[NacsMXer]

Originally posted by ae13291
thank you very much for clarifying that for me buddy

Not a problem ;)

Like you said, checking the oil level on a dry sump motor is a little more involved. You can't just check it cold like you do on your car since there's no "pan" for it to drain back into.