06 engine failure repair

Had the motor go on my 06 WR450. Tore it apart and this is what I found. The head and valves are fine. The rod bearing is shot, the piston is scarred/shot, The crank moved over enough to grind the bearing retainers and bolts off. the cylider looks good except for 1 little spot where the plating got worn through. Can the cylinder be fixed, is it worth it? I looked for the crank/rod assembly in the TT store, but only found listings up to 05, where can I get it?

I will post the pics when I get them loaded in the puter.

Thanks

John in Vegas

how many miles on that bad boy?

Dont know, but I went through a lot of tires.

The problem was overheating and low oil. Dont know where the oil went, but I found the water leake, a little too late.

John in Vegas

Dont know, but I went through a lot of tires.

The problem was overheating and low oil. Dont know where the oil went, but I found the water leake, a little too late.

John in Vegas

thats a bummer...you thinking Big Bore?

Here is the case minus the bearing retainers

day2028.jpg

the retainers at the bottom of the case

day2033.jpg

I thought I had the pics of the piston and cylinder, I guess I will get them tomarrow.

John

thats a bummer...you thinking Big Bore?

Thought about it, but I still need to figure out the cost of either stock or BB and count my pennies

John

Johnny,

I had the same thing happen on my '05 Wr450, which according to posts on TT is identical (engine wise) to the 06. So the '05 in the TT store should be OK.

Bought mine secondhand and it turns out it was owned by a less than careful previous owner who allowed the oil level to get to low.

The rod bearing was shagged and had so much up/down movement.

This resulted in a damaged piston / rings and cylinder.

I looked into the cost of Nikasil replating but the cost was not that much less than a new cylinder from Yamaha, so I bought a new cylinder.

Good news is after the rebuild and 7000km she's running sweet.

Call the TT store or e-mail them...while they don't list the parts you are looking for, they CAN get them...that Harry is a resourceful guy. As far as pricing, if you can find the part number at the Yamaha Fiche site, you can enter it in the search box on TT OEM and get a price as well.

When I rebuilt my 426, the cylinder was tapered a bit too much. I looked into the cost of sending it off to be stripped and replated. By the time I paid for that along with a piston kit (or a new OEM cylinder and piston) and a new piston and rings, I would have been within about 25-30 bucks of the cost of a Luke's Racing 444 kit. I would expect the same holds true for 450s...

Don't know about the exact parts you need, but these guys had great pricing a while back. Use the search engine here for OEM parts to find more sources.

http://www.zanottimotor.com/

For your cylinder you can send it out to be replated by Millenium Technologies, I have used them in the past and they do great work. However, through the TT OEM store you can buy a brand new cylinder for just slightly more after you figure in the shipping expense back and forth to Millenium.

thanks for the help and info. The cost is slowing the rebuild a little so I probably wont have anything to report for a while. I have to use the $$ to keep the bikes that are still or almost running alive. Just picked up a "classic" CR500 that hopefully only needs the piston and rings done (they will be here Fri.) and my RM250 could use some new rings.

John

Although the cost of a new cylinder is similar to replating, remember that millenium technologies plating will be somewhat superior to that of oem yamaha. In my experience, the plating is harder and tends to resist damage more than that of the oem plating. just my 2 cents.

-Alex Galeczka

Service manager/Sr. Engine builder

CSA Performance

Almont, MI

(586)939-RIDE

Thats good to know and I will keep that in mind

Had the motor go on my 06 WR450. Tore it apart and this is what I found. The head and valves are fine. The rod bearing is shot, the piston is scarred/shot, The crank moved over enough to grind the bearing retainers and bolts off. the cylider looks good except for 1 little spot where the plating got worn through. Can the cylinder be fixed, is it worth it? I looked for the crank/rod assembly in the TT store, but only found listings up to 05, where can I get it?

I will post the pics when I get them loaded in the puter.

Thanks

John in Vegas

If you are still checking on this thread you should just drop the money while you have it broken open and go 490 http://www.maxpower-engines.com/big-bore-kits/yz-wr488ice.htm

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