My 06 WR450 just seized on me Here is the timeline of events.


-April 22, buy brand new 06 WR450.
-Do all free mods (AIS, debaffle, snorkle removal, airbox cutouts, YS throttle stop, grey wire)
-JD Jetting kit
-200 miles, couple 1'-2' deep water holes were ridden through, with 3 oil/filter changes, nothing suspicious, life is good
-Get suspension revalved, install myself.
-60 more miles water-free miles, life is better
-Oil change, notice milky oil, scratch head, put in new filter and yamalube.
-Run 5 miles, notice slight differences in engine sounds, but still running strong as ever.
-Run 5 more miles, hit one 1' deep creek
-Idling around in parking lot and all of the sudden SEIZE  
-Starter just clicks, kick-starter stuck, roll start = no luck.
-crack frame plug, oil comes out
-open oil fill plug, lay almost on ground, oil comes out, looks clean.

So, I took it to the stealership to see if it will be covered under warranty.  Won't know what they say until next week.

After searching around a little bit, my best guess is water pump seal?  I ran through some water, but never submerged it and only went through at about 5 mph.

If it is the water pump seal, I guess it would be covered under warranty   If not, should I rebuild or replace?  Is there any hope left for this engine even if it does unfreeze?  I saw an alost new 06 engine on eBay for 2200.  What do you guys think?

If the dealer pays for this, kiss his feet.  Usually, warranty is 30 days--- it's a competition motorcycle.

They should cough up, they do in Australia for this type of thing.

Sounds like it wasn't your fault anyway, regardless of how/where you rode the bike.

It will be easy to fix, it just might cost a bit if you scored the bore.
It could be something to do with the gears....

Mutu said:

not after 30days.

I was blame it on riding deep water crossings but I realized that 1. I've ridden through deeper water crossings than that and 2. 1 to 2 feet isn't all that deep.

Do you have the crankcase breather routed anywhere besides the airbox? If so, my guess is the motor sucked water though the that hose...

Or, the milky oil could have come from your own cooling system via a faulty head gasket.

Keep us posted on that that motor.

JSanfilippo said:

Yeah, how is your coolant level? Because that would explain the milky oil, and if it was really bad (and low) you could have over heated it? Causing it to seize. Just a guess on the cause.

Couldn't possibly be the water pump seal.  Not on these bikes without you knowing about it in short order.  If the seal blew, coolant would spew out through the weep hole and then it would have to get past the oil seal on the other side of the gap.

Thanks for the replies.  The bike is at the dealership right now and I didn't think to check the coolant level But I think I remember seeing coolant in the reservoir after she seized up.

I'm starting to think this will all end up being my fault.  I did have screws and washers circled in red left over after my suspsension installation.  Can anyone identify these?  They may belong to something else in my garage, but I tried to put everything in a plastic bag when I was disassembling:



I remember hooking one hose back into the airbox after putting the subframe back in, so maybe that was the crankcase breather.

I also cut out the airbox cut-outs as part of the "free mods".  But, seriously, if any water got in, it had to be minimal, like a handful or less.  I suspect if they can't find anything wrong, they'll tell me water got in through the cutouts and that I should not have cut them out...

One other thing that I remember is during my last oil change (when the milky oil came out), the frame oil drain bolt was only finger tight The mud around the bolt was moist, indicating that oil had seeped out, but I doubt any dirt could have worked itself back through the threads and into the oil.  Here's a pic of the oil filter that came out with the milky oil, the one on the right is a new one:

SV650WR450F said:

Well the oil filter doesn't look bad at all. Have no clue with the screws.

Best of luck to ya.

Yikes.  I dug through all the beer cans and bubble wrap in my trash can and found the oil filter from the change before the milky oil change:



Left = 2nd to last oil change, Spectro, K&N filter (i think)
Middle = last oil change, Yamalube, Yamaha filter
Right = next oil change (hopefully), No oil, Yamaha filter

It would probably be a better comparison if I could get the filter that is in there right now since I think the K&N filters come purple out of the box, not yellow like the Yamaha filter.  I don't think the different types of oil would look much different in color.

But anyway, my knee-jerk reaction says the middle one is tinted green and therefore coolant has seeped into the crankcase somehow...

Ehh, to be honest the middle one is pretty close to what mine always look like, but a tad darker. The one on the left is what looks wack, but as you said if the filter came purple then it should be fine.

But yeah, sounds like a blown head gasket. Why your bike grenaded I do not know.

Did you change the oil another time after the milky oil change? If so was it normal?

gregwr450f said:

I beg to differ, depends what the problem was. Mate got a new YFZ engine after his bike seized after about 20hrs use.

Another mate got a new CR250R engine after his gearbox shit the tin. They dont have any warranty what so ever.

Good shops are still out there.

Jaycycle said:

No, I had 3 normal oil changes, then 1 milky and the last oil change is still in the case.

This is a real mystery, I hope they can find the cause without doubt...

Mutu said:

Maybe in Australia... not so much here in the US.  I'm prepared for the worst.  I just hope they tell me before the new 450 engine on eBay gets sold.

Looks like a head gasket or cracked cylinder to me. Not good news either way but certainly not the end of the world. Make sure the diagnosis is correct and if thats the problem buy the parts that failed and whack it back together. A complete engine changeout is a bit extreme. Remember that the dealer has descretion and can either offer any part of the repair at minimal or no charge. Maybe you can get them to give you the parts and you pay the labor. They will negotiate. Good luck.

ccoates445 said:

I like your optimism.  I certainly hope I get a chance to disclose this dealer's name and sing praises for them

(one of the "otheR" local dealersHiPs Has already lost my business down here and for good reason )

Just got word back from the Dealership, one of the intake valve springs broke.  And they let me see it

I'm about 30 days past the 30 day warranty.  They called Yamaha to see what they could do and they said that Yamaha is offering to pay 600+ in parts.  There will be 400+ in labor charges that I would have to soak up.

Bittersweet (bitter like Keystone; sweet like watermelon, but not like candy).

So, I ask the dealer if it would help if I called Yamaha personally.  He said "sure, here's their number, and you'll need your VIN number, let me print the parts list out for you too".  Way to go dealer.

So, I spoke with Yamaha and they told me everything I expected to hear and I didn't say much, just requested to have the whole thing paid for, parts AND labor.  "Hang on a second, let me check something"... ... ...  "OK, blah blah blah, blah blah blah, so we want a happy Yamaha customer, we'll pay half of labor".  I say "Deal".

Bittersweet (still bitter like Keystone; but sweet like Big League Chew(grape)).

So, free parts courtesy Yamaha, 6 hours of labor at 70 bucks/hr (reduced to 35 bucks/hr courtesy Yamaha) = 695 + 420 = $1,115 total; 1,115 - 695 - (420 * .5) = $210 out of pocket.  I'm happy.

As for you guys, the dealership said they've never seen a valve spring break.  I haven't searched the forum yet, but it sounds freakish.  

I asked about the milky oil and the mechanics best bet was external water (read: creek water) cooled off a hot engine causing condensation within and milking the oil up. That a pretty good reason to change your oil every ride if you ask me.

Bottom line:  Milky oil had nothing to do with seizure; Intake valve spring broke; Yamaha paid for parts and half of labor even though i was 30+ days past warranty.

EDIT: The engine wouldn't turn over because the valve made it into the the cylinder preventing the piston from moving any further up.  I suspect when I felt the slight differences in power, the spring had already broken and the valve was just bouncing off the piston... not sure though, just a guess.   But the engine definitely stopped when the valve got bent and stayed within the cylinder.

Sounds good! Glad you got it worked out. Man, that spring must have really ****ed everything up in there??

Jaycycle said:

Yes it did.  Parts list:

valve, intake 2
valve, exhaust
spring, valve outer
spring, valve inner
cotter, valve
lifter, valve
seal, valve stem
seal, valve stem
retainer, valve sp
cylinder head assy
gasket, cylinder head
gasket, cylinder
pin, dowel
ngk spark plug
piston (std)
piston ring set
pin, piston
circlip
gasket, tensnr case
gasket, exhuast pipe



EDIT:  Hey, if anyone has a suggestion on different parts I can get to get max performance, let me know!  I asked them about a YZ cam and if it would reduce my low end torque and they agreed.  I want to keep my low end

The mystery parts are as follows...

The phillips head screws are likely the ones that hold on the black triangular piece that covers the airbox on the right side.  The spacer goes to the collar that holds the airbox boot to the intake side of the carb.  The bracket with the two fingers goes between the subframe strut and the exhaust midpipe on the right side.  The hex bolt may be a seat bolt, a subframe bolt or an exhaust bolt.  I believe it's a 10mm, possibly a 12mm, which are used all over the bike...SC