Engine seized.

[JungsukLee]

I bought a 2006 gz250 couple of months ago.
and suddenly engine was locked.
So I went to a mechanic to check out what issue is.
then they said it might be piston and cylinder problem
So they suggested me to replace whole engine.
However, I'm pretty good at toy.
So i bought a online manual which has good colorful pictures in it and it is reasonable price.
few days later i rented a small storage and started to remove the engine from frame.
day by day, I disconnected every bolts and cables.
Finally I found out that piston and valve face were damaged.
I guess it's because lack of engine oil and high RPM.
I will upload the pictures here when i take pictures of it.

By the way. Mechanic estimated engine replacing for $ 800 to $900.

I wish this would help people who get stressed out with seized engine.



A piston was damaged.






Cylinder head was damaged too. click the image to see big size image.





one of the valves face was broken.

[JungsukLee]

PS before I found out what issue is.
I tried to rotate engine. but it stopped at some point.
Now i guess a broken valve face blocked piston to move up.

[Water Warrior 2]

Is the cylinder wall scuffed badly or otherwise damaged ?

[JungsukLee]

please check this out and let me know whether i have to replace whole cylinder head or not.
cylinder head itself is so expensive.

[Water Warrior 2]

My unprofessional opinion is the head is done for. It took some severe thrashing from a loose valve top bouncing around. The other valves are probably done for too. If the cylinder is badly scuffed you may be in the market for a cylinder and complete head to make things right.

[geezer]

im with ww for the most part, buuuuut,i think the head is salvagable if the valve seats are undamaged. if you put it together and it passes a leakdown test fine, then other than a slight performance decrease(or a huge one, idk) from the damaged crown of the head you might get away with putting it together. who knows maybe you can take it to a machinist and get it evaluated. maybe he can repair the damage for a good price, good luck@! :rawk:

[Blitzburgh7sb]

Sorry about your bike troubles. I wanted to say thanks for sharing the info and pics. Good breakdown, one that I have not had to do yet. Hope you get it running without too much money spent.

[Cooteboy]

I just purchased my bike in this very same condition - but, luckily I knew that when I bought it.

1st thing - what does the cam journal look like? (the area where the cam rides in the head and valve cover) On my bike, both were worn beyond belief - which caused the cam to wallow and flop around - which caused it to jump teeth on the timing chain - which caused the valve to be down when the piston was coming up. Ouch!! :skull:

Heads for these bikes are EXTREMELY expensive if you purchase it through Suzuki or if you can even find a used one. If the cam journals are worn - which they probably are - the head is garbage at this point and, your best bet is on eBay. Look up a GN250 head, or LT250E - I found many on there (complete with Cam and all) for $150 - in like new condition. Make sure the one you're getting has four valves and looks just like yours - and most importantly, the cam journals and cam have no signs of scoring.

I bought one off of a 1986 Suzuki LT250E, then purchased a new piston with rings and wrist pin for a GN250 and, honed out my jug. Head with shipping was $100, Chinese piston and rings ran me $25. Gaskets were $12 from the same manufacturer/seller. Had I needed a jug also, they had a kit with jug and matching piston with gaskets for $90 with shipping. So, for around $150 - $250 you could have a running bike again.

It's worked well for me so far ... all 20 miles I've put on the bike :biggrin: . I would have rather opted for the Suzuki piston set but, I'm poor after purchasing the rest of the body parts I needed.

Good luck - if you've gotten the bike down this far, I'm sure you can fix it up! If you need any of those eBay listings, just PM me.