Completely Destroyed my YZ450 motor - what to do now?

I've got a 2003 YZ450F that I picked up this winter for what seemed like a very good price - $2300. I was riding it last weekend when the motor completely grenaded. Unsure exactly what happened, but a mechanic friend of mine tore it down and it looks like pretty much everything went.

Valves / cylinder / crank / piston / crankcase (got mashed by the crank) / probably the head are all pretty much destroyed. What are my options here? My mechanic friend can rebuild it, but I would have to pay him for his time. Any ideas how much this will cost me? Is it worth doing? Should I just part the thing out and look for another one? It doesn't seem like picking up a used motor is easy/common.

You can find used motors on ebay, but they are a gamble. To rebuild it with all new parts will cost a lot, especially if you have to pay for the labor. Seeing the price you payed for it, if the rest of the bike is in good condition I would part it out and buy another bike. I think that is the best way to cut your losses and get the most back from it.

2weelz on thump talk has an 03 motor that runs good for $900..

I would get several quotes to rebuild the motor and/or replace the motor with a new or used one or build a big bore out of it. Just remember if you buy used, tear it down to check it out and replace worn or high wear items to avoid the same fate.......go with the BB kit...you won't be unhappy. :)

That sucks dude. Scary thing buying a used four stroke. Good luck, I hope everything works out for you.

thats a tough decision, rebuilding a motor on my old 05 kx 85 cost me 1500!

So i think you are best off selliing it

Anyone have any thoughts on parting the bike out? I have no idea what the parts go for used. Just throw them all up on ebay?

thats a tough decision, rebuilding a motor on my old 05 kx 85 cost me 1500!

So i think you are best off selliing it

Probably because you got nailed with labor fees. If you did all the work yourself, it probably would have only cost around $500.

Probably because you got nailed with labor fees. If you did all the work yourself, it probably would have only cost around $500.

385 for labour so no not 500 bud

sooryy:cry:

385 for labour so no not 500 bud

sooryy:cry:

So what on Earth did you have done?

Even if the engine completely gernaded, an 85 should need cylinder replating ($200), top-end ($100), and bottom end ($200).

So what on Earth did you have done?

Even if the engine completely gernaded, an 85 should need cylinder replating ($200), top-end ($100), and bottom end ($200).

ill find the bill later and read stuff, just lil things that add up

ill find the bill later and read stuff, just lil things that add up

I would love to see that bill. Must be a lot of "little" things.....holy cow!!!

I would love to see that bill. Must be a lot of "little" things.....holy cow!!!

ya it was kinda redonculous, they had to send parts of to get replated or domething alobg that:confused:

ya it was kinda redonculous, they had to send parts of to get replated or domething alobg that:confused:

I Hope for that much money you had your parts re-GOLD PLATED. Sry to hear about that, but you got taken. If you ever need to do any repair work like that again, get a manual and post it up on here and someone will be able to help you through the process so that way you won't be out so much money so unnecessarily next time.

will do, i just sold 2 weeks ago

glad i got rid of it, but that lil deamin screamed(neighbors didnt likke that)

If you end up parting that 450 out let me know I have been hunting for a good rear wheel for a full time paddle mount. I hope I am not coming off like a vulture I really feel bad for you. These new four strokes are sweet but when they blow it's nasty on the wallet.

Do yourself a favor and take the time to research how much parts are going for on Ebay.

Last summer my wife's CR125 came apart at around 20k rpm.

I talked to the local race shop and spent a long time looking through Ebay. I tore that bike down to every last nut, bolt & part that was salvageable and sold it peice by piece. In the end we made over $2,000 on a bike that would have been worth $1,100 running!

It took me hours to tear it down, take the pictures, get it all online and ship it. But it was worth it in the end.

Just a little info for you:ride: If you decide to go that route.

I think you should fix it.. if you pay $900 for a motor that puts you about where you should have paid for it anyway

I think you should fix it.. if you pay $900 for a motor that puts you about where you should have paid for it anyway

I know it's up to him. He could part it out, get almost all his money back and put it towards a newer bike.

With it being an '03 there's no way I'd even consider dropping $900 on it. That bike would laying in pieces in my garage being sold to the highest bidder.

If it was an '05, yeah maybe.

These are just throw away motocross bikes, not antique Harleys.

Four strokes are reliable and predictable. I say if you blew the motor you had to of noticed something going wrong with the bike before you blew it. I don't know maybe it's because I've always owned yz's and did routine maintenance. Do yourself and favor and check valves be4 you buy or just go with a new bike.

One thing the 03yz450f has on newer bikes is the abrupt hit.

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