Engine seized; Found the problem, What else do I need?

J

jquest

Found out what caused the seizure on my 03 yz250f. (check pic below) Instead of replacing the valves, I was thinking of buying a used whole cylinder head in good condition for a very good price. It comes with everything including the valves. Or should I just replace that one broken valve?

Here is my list of parts I think I should replace. Is there anything else that I am missing? Would appreciate your input!

Piston & Rod set

https://www.ebay.com/itm/Wiseco-Pis...Rod-YZ-250F-2003-2004-4872M07700/372128885140

Crank Bearings (Should I?)

https://www.ebay.com/itm/Yamaha-YZ2...s-Kit-01-02-03-04-05-06-07-08-09/323253706253

Cam Chain

https://www.ebay.com/itm/2001-2013-...-Cam-Timing-Chain-94591-53114-00/172152667474

Complete Gasket Kit

https://www.ebay.com/itm/Tusk-Compl...gine-Set-Yamaha-YZ250F-2001-2013/401262883774

Viton Valve Seals

https://www.ebay.com/itm/2002-2013-...lve-Seal-Set-WR250-5-Seals-YZ250/122136340676
 

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Trfsrfr

Trfsrfr

How does the cylinder look?
I would do a complete inspection of your head. Check all the valves, springs, etc. Even if you buy a used head, how do you know you're not going to get exactly what you already have, and have it blow up too? It will need to be inspected as well.

If you tear the bottom-end apart to do the bearings, you're basically looking at a full rebuild, and you can plan on spending around $1500.00. But if the rod is bad, you might as well...

Just some things to keep in mind.

Welcome to DBA!
 
PALMER84ONE

PALMER84ONE

Looks about right. Seal and gasket set main bearings, crank, piston kit, cam chain, manual, tools. Inspect valves and guide when removing for new seals.

700 will cover parts.
 
2strokesteve89

2strokesteve89

jquest:
Found out what caused the seizure on my 03 yz250f. (check pic below) Instead of replacing the valves, I was thinking of buying a used whole cylinder head in good condition for a very good price. It comes with everything including the valves. Or should I just replace that one broken valve?

Here is my list of parts I think I should replace. Is there anything else that I am missing? Would appreciate your input!

Piston & Rod set

https://www.ebay.com/itm/Wiseco-Pis...Rod-YZ-250F-2003-2004-4872M07700/372128885140

Crank Bearings (Should I?)

https://www.ebay.com/itm/Yamaha-YZ2...s-Kit-01-02-03-04-05-06-07-08-09/323253706253

Cam Chain

https://www.ebay.com/itm/2001-2013-...-Cam-Timing-Chain-94591-53114-00/172152667474

Complete Gasket Kit

https://www.ebay.com/itm/Tusk-Compl...gine-Set-Yamaha-YZ250F-2001-2013/401262883774

Viton Valve Seals

https://www.ebay.com/itm/2002-2013-...lve-Seal-Set-WR250-5-Seals-YZ250/122136340676
Click to expand...

Your not gonna just slap another valve in there, the seat looks done. You'll need to have a new seat put in as long as the head is not cracked.
 
Trfsrfr

Trfsrfr

2strokesteve89:
Your not gonna just slap another valve in there, the seat looks done. You'll need to have a new seat put in as long as the head is not cracked.
Click to expand...
Yeah. I didn't even look at the photo until you mentioned it, but yes, its toast.
Looks like OP will be buying the used head.
Call it 1800-2000 after you replace all the other goodies "while your there"...
(I'm referring to OE parts BTW)
 
Last edited:
PALMER84ONE

PALMER84ONE

Hahaha.. Didn't even look at the photos on my phone. The head has gone with the wooly mammoth.

700.00 OEM bottom end/piston. I just rebuilt a CRF250X, and a YZ426 OEM. The Honda was more than the Yamaha by about 250.00 bucks.
400+ to have a new head and then add another 200 for any work beyond that.

You don't need to look at it as over 1300 to get that back to running. Unless you have more damage that photos.
 
Trfsrfr

Trfsrfr

PALMER84ONE:
Far cry from 18-2K.
Click to expand...
It is, but if you look back at my first post I said 1500. And if you add in the new air filter, the broken fender, the throttle cable and everything else...I'm not that far off.
It like when I do a head job on a car; sure the NEEDED parts are 1000, but the new spark plugs, plug wires, cap, rotor, and fuel filter...and why would you refreshen the combustion chamber and not replace those parts...?
 
2strokesteve89

2strokesteve89

Trfsrfr:
It is, but if you look back at my first post I said 1500. And if you add in the new air filter, the broken fender, the throttle cable and everything else...I'm not that far off.
It like when I do a head job on a car; sure the NEEDED parts are 1000, but the new spark plugs, plug wires, cap, rotor, and fuel filter...and why would you refreshen the combustion chamber and not replace those parts...?
Click to expand...

Cap and rotor? What you talkin’ about Willis?
 
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