sunday's carnage

[yellow416ex]

just thought I would share a few pics of what I found when I tore my motor apart today

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1592.jpg

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1596.jpg

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1593.jpg

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1594.jpg

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1601.jpg

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1605.jpg

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1606.jpg

so much for waiting until the end of summer to freshen up ha ha

[Newrider08]

in the words of Mr Chris Farley < RIP

WHATD YOU DO lol

That sucks man, how in the heck did you do all that?

[DirtMonkey]

What happened did you run it dry??!!

[F150 Rider]

that aint good!!

[yellow416ex]

Im pretty certain it wasnt dry, but it must have been really hot because the sleeve slid down about 1/2 inch so the rings popped out and caught the top of it. that will make a motor stop reeeal fast ha ha

[davidw2155]

That would be a nasty surprise to find when tearing down...I bet that stopped you in your tracks when that happened.

[Speedy 400ex]

Dang the whole sleeve did slide down. Is that a common thing to happen?

[yellow416ex]

yeah it stopped pretty darn fast, all I heard was a loud pop and it was done for

I dont think thats a common thing to happen, at least Ive never seen it before. Theres a thick ring at the top of the sleeve to hold it in place and it snapped right off and broke in to a few pieces

[NacsMXer]

Dang, that sucks man...I feel for ya, and your motor lol :eek:

Just curious what octane gas were you running? Were you riding hard for a while when it happened? Just thinking it could have been bad gas maybe.

Great excuse to rebuild it...stronger and more powerful this time :devil:

[yellow416ex]

Originally posted by NacsMXer
Dang, that sucks man...I feel for ya, and your motor lol :eek:

Just curious what octane gas were you running? Were you riding hard for a while when it happened? Just thinking it could have been bad gas maybe.

Great excuse to rebuild it...stronger and more powerful this time :devil:


thanks man, I was running 91 octane. I wasnt riding too hard, we were just playing around at the dunes when it happened. What exactly does bad gas do?

yeah perfect excuse to go bigger and stronger

[hypersnyper6947]

hope all the metal from the sleeve didnt destroy your bottom end too

[NacsMXer]

Originally posted by yellow416ex
thanks man, I was running 91 octane. I wasnt riding too hard, we were just playing around at the dunes when it happened. What exactly does bad gas do?

yeah perfect excuse to go bigger and stronger

Well seeing that you have a Sparks timing advance key, and almost 11:1 compression, that puts you on the edge of needing high octane gas. I would have run 93 at the bare minimum with that combo, but I understand 91 is the highest available in some areas. If you got a bad batch of 91, you motor could have gotten hot, detonated, and caused the damage.

If you didn't already know, octane is simply a measure of a fuel's resistance to detonation. The higher the octane...the more resistant the fuel is. Detonation happens when the combustion chamber gets so hot, that the fuel ignites, even when the spark plug doesn't fire. That mis-timed explosion is what breaks pistons, rings, and snaps connecting rods like twigs.

I can't say for sure that bad gas and detonation is EXACTLY what caused that failure, but it's a likely culprit at the same time. It's one of the reasons I only run straight 110 octane in my motor...I run high compression and i'm not going to chance it.

Also what spark plug did you have in it? DPR8Z or DPR9Z?

Good luck on getting it rebuilt, post some progress if you can :)

[jcs003]

sorry to hear. did it over rev or something? go 500cc FST liquid cooled. i think the kit and motor work is $2500.

[killer400ex]

i hope you know your not supposed to use the advanced timing key on engines that are bored and heavily modifyed, and i think that high compression andoversized piston and stage 2 cam probly did you in, sounds like detonation to me too, not positive but there arent manny other things that can pull that kind of dammage off, wow sorry to hear that bud, i thought that bad rings and some scoring was bad, maybe a valve or 2 but this is quite a pice of work here

[Sanddraging28]

with that kind of damage i would split the cases and check everything else.
i have never seen a sleeve do that!!! thats a new one to me.

as far as what jcs003 said about the 500ex liquid cooled motor. i dont believe FST is doing that kit anymore. the 500ex kit is still available. it makes awesome power. my last 500ex was from FST, the one i have now is a crank works motor

[sc400ex_rider]

WOW BOOM. i never saw an ex do that before. i was trying to figure out how the sleeve slipped but i see the top lip broke off. even if it got super hot or the cylinder was bored a little to much to let the sleeve slip there would still have to be a ton of friction (seized) between the piston and sleeve to break it off. its almost like the old 2 stroke problem when you jump on a cold engine and run the piss out of it and it seizes cause the piston will get hot and expand but the cylinder has not. i think the cylinder was bored wrong maybe letting it rock a little bit until the lip failed. i would not take it back to whoever did it last time. i had a popular local cycle shop f'up my dirt bike cylinder. first they bored it wrong forcing me to up a size on a brand new sleeve then they cracked the exhaust bridge pressing it in. lets just say it lasted about 30 minutes LOL. you definitely have the blow up of the year award so far. you can check the bottom end if you want just to get all the metal pieces out but the way that one came to a sudden stop i doubt that it pumped ant metal shavings throughout the motor. also if you ride desert you may want to put a fan on it, they work wonders.

[yellow416ex]

Originally posted by NacsMXer
Well seeing that you have a Sparks timing advance key, and almost 11:1 compression, that puts you on the edge of needing high octane gas. I would have run 93 at the bare minimum with that combo, but I understand 91 is the highest available in some areas. If you got a bad batch of 91, you motor could have gotten hot, detonated, and caused the damage.

If you didn't already know, octane is simply a measure of a fuel's resistance to detonation. The higher the octane...the more resistant the fuel is. Detonation happens when the combustion chamber gets so hot, that the fuel ignites, even when the spark plug doesn't fire. That mis-timed explosion is what breaks pistons, rings, and snaps connecting rods like twigs.

I can't say for sure that bad gas and detonation is EXACTLY what caused that failure, but it's a likely culprit at the same time. It's one of the reasons I only run straight 110 octane in my motor...I run high compression and i'm not going to chance it.

Also what spark plug did you have in it? DPR8Z or DPR9Z?

Good luck on getting it rebuilt, post some progress if you can :)

Yeah I wish we had 93 around here, all Ive found higher than 91 is 100 octane. I think Ive got a DPR8Z in it right now

Thanks for the info, I will be sure to post some updates

[yellow416ex]

Originally posted by killer400ex
i hope you know your not supposed to use the advanced timing key on engines that are bored and heavily modifyed, and i think that high compression andoversized piston and stage 2 cam probly did you in, sounds like detonation to me too, not positive but there arent manny other things that can pull that kind of dammage off, wow sorry to hear that bud, i thought that bad rings and some scoring was bad, maybe a valve or 2 but this is quite a pice of work here


I know sparks says not to use it with big bores and high compression, but Ive seen a few people use the key with up to 11:1 so I thought I would try it, probably should have had higher octane. but now i think the key is comin out

[NacsMXer]

Originally posted by yellow416ex
Yeah I wish we had 93 around here, all Ive found higher than 91 is 100 octane. I think Ive got a DPR8Z in it right now

Thanks for the info, I will be sure to post some updates

Gotcha. It's too late now, but you should have been running the "colder" DPR9Z with that motor combo. The DPR8Z plug is for stock or close to stock motors and can develop a hot spot once you start introducing high compression, advanced timing, etc. Colder heat range spark plugs will prevent that.

Stick to the DPR9Z on the new build, it's just added insurance :)

[casiey400ex]

very sad

[michaelopfer]

i've had the same thing happen on a 300ex cylinder last year. we had a local shop build it up one size bigger, and broke it in and rode it for about 10 minutes before it locked up. that happened a years ago, and the quad is still sittin in the shop with the motor apart, I think its from a bad builder who doesn't check there ***t
yea it's a bummer, and good luck with your build.

[yellow416ex]

thanks man, I dont think this was the machine shops fault because it ran great with no problems for a year. I think it was a bad combination of parts and not running race gas

[yellow416ex]

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1615.jpg

heres all the metal I pulled out of the bottom end

http://i136.photobucket.com/albums/q181/wheeliebob/IMGP1616.jpg


I decided to try a little polishing since everythings apart

[DMAXX99]

OILLLLLL lol its kinda important but it sounds like the done it