Rebuilding a Seized 2011 Yamaha YZ450F Motor - [Part 4/4 - DONE!]

The final part of my journey rebuilding a Yamaha YZ450F motor. I seized the engine on my dirt bike and decided to rebuild it myself. This was my first time rebuilding a motorcycle engine and it wasn't anywhere near as hard as I thought it would be! If you're in a similar situation, dive in and try it yourself. If you've got a Yamaha engine between 2010-2013, I have plenty of photos and videos to share if you need help!
#YZ450F #yamaha #motorycle
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[@05c50]

Nice series. Good camera work and explanation of disassembly and re assembly. I applaud your cleanliness, it's often overlooked. I have one comment, one suggestion and one question. 1)I think that you should have shown a little more of installing the transmission into the case, it can be very troublesome to do and it would have been helpful to see you do it. 2) If you're going to use a hammer to install bearings, find something that will drive on the outer race so that you don't damage the balls. 3) We know that the crank/rod seized, but do we know why? The cam looked like it had plenty of oil so it must not have been a lack of oil pressure. Thanks for posting and keep up the good work.

[@danielwadley8225]

Great series. My son was riding his yz450f the other day and it started hammering, not seized but lots of metal in the oil. We were thinking about trying to tear it down ourselves, but although you gave a great tutorial, I'm more scared now to dive in than before lol. Wish you would have shown removing the engine though. He didn't change his oil nearly as often as he should have, I suspect this is why he's having a problem.

[@MrHeresDave]

Next time I rebuild an engine I'll be sure to show the removal! I also was asked to include the transmission removal and install, so I'll do that, too. If you take your time and work in a clean space, you'll be able to do it. If you decide to attempt it and need help, just shoot me a note and I'll try to help ya' out. -Dave

[@outerlimits583]

Very informative man thanks heaps. Makes me confidant to tackle this siezed kx 450 I have

[@grainbrain5704]

awesome series, gonna have to book mark this for when i need to do anything to my 2011 yz's engine :))

[@Venneman417]

great video! Hows the hot rods crank and bearings holding out? Ive heard plenty of stories about them!

[@masonthibodeaux4060]

Did you re-use your head bolts or get new ones? I know torque to yield is typically a one time use. Thanks a ton for the videos though! It's calmed my nerves a bit on rebuilding mine.

[@dannyfranklin434]

How is the Hot Rods crankshaft holding up? My 09 yz450f is blown up I’m thinking about using that brand crank

[@sebastiannieroda4834]

I was rebuilding the exact same motor and when finished I tried to kickstart it and it was as if the kickstarted was seized, it didn’t want to move at all which I’m not sure what the issue could be, once thing I forgot to test was test the valve clearance of my bike. Could that be the issue? Or would it be something like position rings?

[@byrynmiller5228]

How much did this cost total if I may ask I have the same bike it’s locked up and idk what price range I should think I’m doing it myself too

[@MrHeresDave]

Hi Byryn! Sorry this is so late! I spent about $800 or so in parts. I can’t remember how long it took me since I was filming along the way, but I suspect it would take an easy weekend.

[@HolyShitAccess]

I was about to flip, no way it took on first kick. Nice job man hope you get lots of hours out of it.
Also why replace the jug and piston?

[@MrHeresDave]

Thanks, man! Where I live it’s really hard to get parts shipped, so I ordered everything I would possibly need at the very beginning so I wouldn’t have to wait for anything during the rebuild. Thanks for watching!

[@Andrey6042]

Hello, tell me please, what size on piston?

[@MrHeresDave]

I believe it is 97mm.