Engine seized up

My son while riding the 650 at night lost all engine oil via a busted oil line linked to an added oil cooler. He pulled over when the engine made weird noise but I think it's too late. How much of an engine tear down am I looking at? Cost? Thanks for input/advice.

sorry to hear that ..at least he did not coat the rear tire and wipe out ,get hurt,or skid into a rolls royce,.....the kz-ltd 750 motors are the same cases are they not all most a drop in motor...???get a clean one at yard or e-bay maybe and then tear the 650 down with all the time in the world and no worries if it is way toast....try refilling with oil and starting it ...you may get a pleasant surprise...oh wait...you did say siezed right.....good luck...craig

Your just going to need to take it apart one peice at a time and inspect each part. Hopefully it will only be in the topend (who knows) I bet this is one time that xray glass would be helpful to save time and money. It's hard to guess the price until you find the full extent of the damages. All you can do is look for the scared parts and parts that look like they were welded together. Sorry this isn't helpful. Once you know what you need, someone around here will be able to help you out with no problem.

six years ago the exact same thing happened to me.
blew the line at the bottom of the motor and it was too late to save anything.
the rod bearings were wiped out.
i would keep my eyes open for a lower half because i doubt it's in the top end.
at least that was my experiance.
good luck.

Bummer, sorry to hear the engine got toasted. I think you will find rebuilding that motor would be ridiculously expensive even if you do the work. Finding a nice used engine sounds like the plan to go with. Even if you find one that needs a valve job, that's not too expensive. Pistons and rings for the 650's are steep, and the main bearing journals may be trashed on the crankshaft as well.

Just for the hell of it i would try to free the piston refill with oil and try it. what do u have to loose. stranger things have happened.
OK BOYS how’s the best way for him to free the pistons?
U could try penetrating oil through the plug holes. come on guys i know u have better stuff than me . isn’t there a can of something just for this?
if that doesn’t work u could pull the head and hit the tops of the pistons with a wood block and hammer. didn’t someone just go through this here? Who was that. man I’m getting old.
:S

I fried a 350 BSA engine when the oil line between the engine and oil tank vibrated off at 75 mph. In my case everything seized locking up the rear wheel and leaving an impressive skid mark until I thought to pull in the clutch. The engine was totally trashed - everything was welded together. Those engines were dry sump, so the external reservoir and lines going to it were a necessity. External oil lines are a very deadly single point of failure. It sounds like your son shut down the engine before it seized, so the damage may be less severe. When you do get your bike fixed you may consider eliminating the oil cooler as KZ650's don't need them. Good luck. Ed

mark1122 wrote:

Just for the hell of it i would try to free the piston refill with oil and try it. what do u have to loose. stranger things have happened.
OK BOYS how’s the best way for him to free the pistons?
U could try penetrating oil through the plug holes. come on guys i know u have better stuff than me . isn’t there a can of something just for this?
if that doesn’t work u could pull the head and hit the tops of the pistons with a wood block and hammer. didn’t someone just go through this here? Who was that. man I’m getting old.
:S

that mighta been me but no luck as it had been sitting a longggggggggggggggggggggg time ....as in.... me love you longgggggggggggggggggggggg time...but worse....
i agree about trying it before doing any thing hard(i'm lazy) re-fill it and bump start it, about four times , with the key off and a really good running start in third gear then.....try and start it...it may be no worse than the inside of some of our running bikes:woohoo:

mark1122 wrote:

Just for the hell of it i would try to free the piston refill with oil and try it. what do u have to loose. stranger things have happened.
OK BOYS how’s the best way for him to free the pistons?
U could try penetrating oil through the plug holes. come on guys i know u have better stuff than me . isn’t there a can of something just for this?
if that doesn’t work u could pull the head and hit the tops of the pistons with a wood block and hammer. didn’t someone just go through this here? Who was that. man I’m getting old.
:S

Mark is it called anti-seize???? (just kidding)

Thanks folks,
a complete teardown is what i gathered. Meanwhile I might look for a re-built depending what the cost is. Looks like this 650 will be shelved for a while. Man just when i had the ignition and fuel issues worked out. It's true that at least my son didn't crash. Back on the drawing board!

Random thoughts, oil related seisures in four strokes generally start furthest from oil pump.since the 650 is of plane bearing design, I would look 1st to cams & bearings. as they are usually 1st to go. if shot, everything down the line is suspect, cam chain, pistons, big end/main brgs. once a seizure has occured, even if things break free. oil presure will be lost and can lead to later failure. sorry to be Gloomy, Just my 2 cents.G

one good thing is i know myself, along with a lot of other members have everything you need to help you rebuild her so you don't have to search e-bay forever.
i'm almost sure i have a crank i can let you have.
i know i have cases.
sounds like a good time to go to www.kzzone.com
and buy a 700cc kit.
if you have to do it anyway, might as well go bigger and do it right.
plus they have added 650/750 cams to their lineup. good stuff!
sucks you have to do this now but man, i've been in your shoes before i heard of this sight.

no fear, just a little set back. we will walk you through it.