Guess that Repair Game!!

[Knips178]

Let's play a game where you Guess the Repair!! (cue cheesey game show music)
Here's how you play, I'll show you pictures of the problem and you tell me how much it will cost to fix! (while this sounds fun, there's nothing fun about what I'm going to have to fix)

The setup is this, a 2000 440ex starts ticking so the valve lash is checked and it still ticks loudly. It was driven 30 yards down a driveway and the tires lockup and the engine dies instantly. When the starter is tried only the gentle humming sound of electricity is heard and no moving of gears. Upon further inspection the following is found...
http://domino.newvisionnet.com/Joey/atv/March%202004/index.html

Now Guess that Repair!!!

:(

[Knips178]

Oh, and if your wondering what those black dots are on the piston head, those would be the intake valves welded to the piston!

I'd say the timing was WAY off or you floated a valve.:(

Order a new piston and everything above that in the head and you maybe OK.:eek2:

[Knips178]

Good guess, but the timing was fine for a full year with no ticking untill the day this happened.

[miken]

Autoadjust timing chain tensioner failure?
Mike -

[Knips178]

another good guess, but the tensioner looks good and has no damage to it. mind you, i'm saying anyone is right or wrong, i'm just letting you know what I found out.

[miken]

Well something broke those valves? Wrist pin gave out and let the piston hit the dome?
Mike -:confused:

[Knips178]

yeah, i agree that is a good possablility, but we'll know the answer tomorrow. Tonight I'm removing the jug and seeing if the rod is ok or not and that will be the final clue.

[miken]

WhoooHooo, I'll take whats behind lucky door number 3. Just kidding, tough luck, was there alot of cylinder damage?
Mike -

[Knips178]

well, what you see in those pics is what I've seen so far. So I have no idea what lies beHIND PISTON NUMBER 1 BOB!
It's tuff to see in the picture, but the center of the head where the spark plug is, there is are huge chunks of metal missing where the valves slammed into the dome. I can't wait to see whats under the piston. ugh

[miken]

Good Luck! I'll check back to see what you find.
Later -

[airheadedduner]

Worn valve guides broke the valve stems:confused:

[Knips178]

do you mean the worn guides made the valves wobble to much or they jammed the valves from moving then they got slammed?

[UglyMotha™]

told ya it wouldn't run on diesel fuel :o

[Knips178]

I disagree it ran great on diesel for a couple of minutes. Had good lowend untill I blew the topend!

[UglyMotha™]

but anywhoo, my guess would be she jumped time and lets just say piston and valves kinda clash together

[Knips178]

Ok, so we have Auto tensioner went bad, the timing was way off and the valve floated, or it jumped through time and the valves and piston time welded themselves together!
Any other guesses?

[Aceman]

I assume the ticking was your valves hitting the piston right from the beginning. Did you just put this 440 kit in? Did you check valve-to-piston clearance before you put the engine together? What are you running for a head/base gasket? Has the head or cylinder been milled down?

[Knips178]

The 440 kit was in it when I bought it a year ago. So no i didn't check clearance. I'm not sure on the gasket. I don't think it was decked. But I would probably agree with the ticking noise being the valves bouncing off the piston. I will take pictures tonight of what I find under the piston and post them tomorrow.

[Aceman]

You probably had weak valve springs that needed to be replaced. How many rpm's was it running when it blew up?

[hondatv]

What cam are you running?
The sprocket flange may have slipped.

[F-16Guy]

Why do I have a feeling that this is going to be another HotCams story?:(

[416mx]

EITHER BAD!!!!!!!!!!! :devil: :eek2: :mad:
Man sorry about the bad luck, I just got mine rebuilt and i would die if that happened to mine!!!!!!! Good luck puttin it back together.

[Knips178]

It is a stock cam and I was running around 4000 rpm at most when it happened. It locked up instantly!

[mustang93]

yum yum valves, that sucks sorry man:(

[Chef]

Maybe the ticking was just showing that it was a time bomb waiting to happen? :blah:

Note to self: Adjust valves soon, make sure ticking stops. :eek:

[Knips178]

Here it is, what i found under the piston and the pictures of the jug!
When I bought this 400ex the person said it had a 440 kit in it, but I've never had it opened up untill now so I never Really knew if it actually had the kit in it. There is a number on the top of the piston, does that number mean anything to any of you? or should i just measure it to see if it's bigger than stock?
Anyway, you may notice the Rod looks tweaked, but the engine rotates fine, even when the piston was still in the sleeve. And amazingly enough the sleeve was not scratched up at all. It will probably have to be bored over just for safety, but it looks to be in good shape.
Now comes the fun part, assuming the bottom end is fine, is this engine worth fixing or can I find a crf450 or yz426 motor for a reasonable price and go that route?

Here are the pics:
http://domino.newvisionnet.com/Joey/atv/March%202004/index.html

[Knips178]

Survey says?

Floating valves!!
Ding Ding Ding Ding!

And the estimated cost to fix back to new?
$1000
Ding Ding Ding Ding!

Oh that hurts. Ahhhh they got me, right in the wallet.

note to self invest in good springs this time/

[Aceman]

Rico and I guessed floating valves/weak springs.

So what did we win??:D:blah:

[Toadz400]

Yea I know how that feels...my rebuild cost me $1000 for my Banshee. Fried everything, top end and bottom end...wasn't pretty...amazingly though, the right cylinder and piston was just fine:huh . My left piston decided to lock up on me one day for no reason, break off the rod, fry the crankshaft...etc..lol, well $1000 later and it runs just fine:p

[Bean]

call me dumb, but i still dont see anything wrong with that motor

[Knips178]

Well, that's understandable. Sometimes it's tuff to see the problem when there is so little of it.

Note to anyone that may read this:

IF YOUR QUAD IS MAKING A WEIRD NOISE, STOP IT IMMEDIATELY AND HAVE IT CHECKED OR THIS IS WHAT COULD HAPPEN!!!

and trust me it's not fun, or funny.