Kawasaki ZX-10R Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
667 Posts
Discussion Starter #1
My son's 636 broke a rod & created a large viewing port in the cases a couple years ago & now I'm finally going to tear into it.

I've done top ends before but this will be uncharted territory for me.

Dont try to talk me out of it, my puny mind is made up.

Got a manual coming........will read that info over a couple or 3 times & then diving in.

Wondering what major issues I should keep in mind or specialized tools I may need.

I expect i may have issues with splitting the cases & putting the crank & bearings back in. Figured I'd likely have to go to a shop and have them do that part maybe.

Any advice other than "DONT DI IT!!!!" is welcome :mrgreen:
 

·
Registered
Joined
·
1,025 Posts
taking it apart is the easy part.you need to get yourself an accurate torque wrench for assembly.
Why did the rod snap? was the motor knocking right before that? in that case you will need to send the crank off to get repolished. then you will have to measure the correct bearing thickness for that rod. assembly is not that difficult theoretically, but i would leave that to somebody who has done it a few times. you dont want to have to go in there again.

oh and BTW, a cheaper solution is to just buy a new motor
 

·
Gen 5 Now!!
Joined
·
1,128 Posts
:+1: if you need new bearing (crank and rods)which you should replace is going to run about $200 plus all new gaskets and id check the other rods to see if any are bent besides the broken one. you will need a couple of torque wrenchs, flywheel puller, possibly some torx bits, multiple allen keys, 8mm-17mm (atleast) sockets, and im sure im forgettin a few. plus while ur in there check the valve clearances with a good set of feeler guages.
oh and BTW, a cheaper solution is to just buy a new motor
 

·
Registered
Joined
·
363 Posts
You'll probably need a new crank. If you put a hole in the block (which is pretty common) the crank is toast. A complete motor is the way to go.
 

·
Registered
Joined
·
667 Posts
Discussion Starter #6
I have a set of good used cases.......cost $ 0

Used motor will run $1200 +.......an 03 636 isnt worth much more than that running.

I may get in there & find that too much is shot & sell off the parts but 636 engine parts dont go for much either

have those tools & more

Figured to replace all the bearings anyways.

Dont think the engine was knocking........just running @ 150 mph .

I think it was low on oil. Speculation on my part.

why should the crank be bad? Do you mean the journal is probably scratched?
 

·
REPOST Enforcement Mod
Joined
·
13,548 Posts
why should the crank be bad? Do you mean the journal is probably scratched?
Not only is it probably scored badly from the rod letting go and metal flying around in there, but you'll need to check each journal for an out of round condition. The crank bearings used pressurized oil. In your case, once the oil blew out of the cases, there was no more oil getting to the crank. Once the rod let go, there was an open oil port and nothing to get the pressure up on the remaining cylinders with the remaining oil in the case. I'd bet more than just the 1 crank journal are hosed because of oil starvation.

I just got done helping a friend rebuild his Triumph S3 motor that spun the #2 bearing. Crank was completely worthless because the #2 journal has so flattened out there was nothing to do.
 

·
Registered
Joined
·
667 Posts
Discussion Starter #9
Not only is it probably scored badly from the rod letting go and metal flying around in there, but you'll need to check each journal for an out of round condition. The crank bearings used pressurized oil. In your case, once the oil blew out of the cases, there was no more oil getting to the crank. Once the rod let go, there was an open oil port and nothing to get the pressure up on the remaining cylinders with the remaining oil in the case. I'd bet more than just the 1 crank journal are hosed because of oil starvation.

I just got done helping a friend rebuild his Triumph S3 motor that spun the #2 bearing. Crank was completely worthless because the #2 journal has so flattened out there was nothing to do.

Good info. makes sense. Thanks.
 

·
Registered
Joined
·
667 Posts
Discussion Starter #10
yes, the reflective finish is not reflective anymore. And motors for 636 are not 1200. ive seen a few of them go for half that on CL. just keep your eyes open

for that kind of $$ yes, I'd switch motors. I have watched ebay off & on for a couple years now & havent seen a one that looked decent for under $1000+ shipped.

I'll pull it apart & keep my eyes peeled for a motor at the same time. If you happen to run across one I'd appreciate a PM for a heads up if you happen to think of it.

Great info guys.
 

·
Registered
Joined
·
667 Posts
Discussion Starter #12
the hole is behind the cylinders .....

I feel your pain


:mrgreen:


Could I check for bent crank by careful use of a dial indicator before I pull the cases apart?
 

·
Registered
Joined
·
363 Posts
Doesn't matter where the hole is. The fact that there is one tells me the crank is probably bent.

If the crank spins easily in the cases with no rods attached you might be Ok. All you really need is to suspend the crank on both ends (remove the main 2, 3, and 4 bearings) and put a dial indicator on those crank journals and see what you find. The manual will spec. how much run out is acceptable.
 
1 - 15 of 15 Posts
Top