KZ700 locked up?

Well i rode my kz700 to school today (as usual) it ran perfect all the way there and when i got out of school it fired right up, ran fine, then the trouble started when I hit the highway. When I got on the highway I was doing about 80 (my normal cruising speed) and I heard a rubing noise, it was a weird noise, almost like the wind blowing but when I let go out the throttle the noise went away well when I gave it gas the motor just quit firing and it died (almost like it ran out of gas) I pulled over to the side of the highway and the motor has been locked ever since! I pulled the plugs and they all look great (not smashed and they are burning nice) so i am thinking it is the crank bearings? I am really stumped and i am a beginner with these inline 4 cylinders but im not afraid to tear into it, im a strong believer of "if you watch how you tear it apart it will go back together the same way" Well do you guys have any suggestions? Like I said i am really stumped on this one!

THX in advance
BLAIR
RIDE TO LIVE, LIVE TO RIDE...
TOMARROW

It would be really difficult for the crank bearing to lock up the motor, if they seized to the crank they would just spin in the case (and pretty well destroy the case).

If the motor is locked up solid, then more than likely it overheated and seized the pistons to the cylinder walls. Take the head off and take a look.

I think I may pull the head off today.....but I am worried about the timing, I have no clue how to adjust the timing so is there a way I can take it apart without changing the timing?

The factory service manual does an excellent job of describing how to set the cam timing when reinstalling the cams. The KZ/GPz750 procedure is the same (same motor), so if you don't have a manual you can download one HERE .
Read it and get familiar with it before you start.

Just double check everything before you turn the crank.

Post edited by: steell, at: 2007/05/05 10:10

Thanks very much for the link, I didnt have a manual and I couldnt find one anywhere, I am guessing the only way to do this is to take the engine off of the bike, so I am off to the garage to do that now. I will check back frequently if i have questions!
THANKS AGAIN



BLAIR

Above advice is sound. First read the manual. Pulling motor may not be necessary, at least not yet. Can probably pull head, jugs, and pistons without pulling motor. And motor will be "smaller" and "lighter" and easier to pull later, if need be, absent the head and jugs.

Meanwhile, how does the oil appear? Is level low or overfull? Thin (fuel contaminated)? Black? Burnt? Did the oil pressure light turn on before the motor froze?

Won't hurt to put JB Blaster into spark plug holes and allow to sit for a few days. Probably won't help either, but might possibly loosen things up.

FSM trouble shooting guide (for large fours) lists several reason for seized engine, including valve, lifter, piston, crankshaft, rod bearing (either or both ends), tranny gear or bearing, camshaft, and primary reduction gear.

Also numerous reasons for lubrication failure and/or overheating.

Wishing you success and Good luck with the repairs.

Alright, the motor is tore down and it is deff. the rod bearing on the number 4 rod (see attached)now a few questions, how do i fix this? do i get the crank turned and a new set of bearing for all of the rods? also is an attached pic of a few part we found laying in the oil pan. they consist of a small spring,2 circlips, and a ball bearing. We found out where the ball bearing goes but are stumped with the cir clips and spring. THANKS FOR THE HELP SO FAR!

i89.photobucket.com/albums/k220/jordan172005/100_1228.jpg

i89.photobucket.com/albums/k220/jordan172005/100_1225.jpg

del

If the crank needs turned, then you will probably have to replace it as I have not seen any undersized bearings for it anywhere. I think Kawasaski only sells .006" undersized bearings at most.

Check the parts diagrams at Kawasaki.com and see what other cranks will work, I suspect any of the KZ/GPz750 cranks will fit, except for maybe the 82 GPz750 crank.

hmmmm.......the whole crank looks perfect except for where the bad crank bushing was......im thinking i can maybe use 1000 gritt sand paper and then buff it with a dremel, then use stock bushings, what do you guys think? where would be the best place to buy the crank bushings? THANKS A TON!!!!

P.S. I found out where all of the loose pieces go except for the smaller circlip and the spring:)
Oh I forgot to mention, wonder why it broke? i dont want to do all this work and what ever caused the problem, do it again


BLAIR

Post edited by: 84kz700, at: 2007/05/05 22:48

Don't do the "Bump" thing, the tech forums are not that active and it just wastes space.

Generally, the only reason bearings self destruct is lack of lubrication, can you post pics of the rest of the bearings?

Just a request... when you find what the cause to a problem was or where lose parts came from would you mind sharing that information with us. That way everyone in the forum benefits. Thanks!

Best of success!

Post edited by: bill_wilcox100, at: 2007/05/06 12:39