This one was a little weird

[WFO Speedracer]

Kawasaki ZXI 750 , I got it in a package deal with a double galvanized trailer, an XLT800 and a Kawasaki Teryx 750 UTV, all for $600.00 , I diagnosed these for the customer last Summer , two dead engines one dead jet pump , the Kawasaki would turn so far and stop in either direction hard , both are saltwater junk so taking this apart was a nightmare ,.

The exhaust manifold wouldn't come off the cylinder and I had to take the engine loose to get at the two cylinder nuts under the manifold, one nut didn't come loose , it took out the stud with it . I had to beat the rear piston out to get the cylinder off, broken piston bits were already everywhere, I removed what I could get to and it still wouldn't turn over freely.

That's when I saw it , before I tell you what the problem was take a look at the pics and see if you can find it.

So far I have a good cylinder that has an exhaust manifold stuck to it , the head is trashed , crank is trashed , not sure about the cases , I will have to pull it all down and check them , not sure on the electronics because it would not spin over.

They must have had this thing hung wide open when it gave up the ghost .

 

[Big Kahuna]

nothing jumping out other that half the bottom piston missing.

 

[WFO Speedracer]

The crankshaft has twisted at the rear rod pin , if you look closely you can see how the counterweights don't quiet line up anymore , it looks like they are stepped , the axial runout spec on those counterweights is like .004 -.010mm , a slight amount of excessive runout causes a crankshaft imbalance , a large amount like this causes the crankshaft motion to become elliptical and since the cases try to hold the crankshaft in alignment something has to give.,

I am assuming the counterweights are actually contacting the cases when you spin it , like I said it must have been wound un tight when it let go. There is a good chance that everything there is cashed.

 

[Big Kahuna]

ok, first pic I can see something is "Off", 2nd pic cannot tell anything, they look 180 degrees from each other.

 

[WFO Speedracer]

ok, first pic I can see something is "Off", 2nd pic cannot tell anything, they look 180 degrees from each other.

Not twisted at the center pin , at least not that I know of , it's twisted at the rod pin.
At some point the jet pump locked up on this machine and the rubber dampener was completely missing, there is no telling what went on here , funny part is the cylinder looks good, if the manifold will separate from it, it's stuck on the studs with salt water corrosion.

 

[WFO Speedracer]

I decided to try and separate the cylinder and exhaust manifold , I knew they were not coming apart without destroying one or the other, I chose the exhaust manifold.

I started by drilling some 1/8" holes around the studs , about six holes around the longer studs and two to three holes on the other two then I doused them with penetrating oil , I know false hope abounds here in abundance .

Then I inserted a long wooden wedge and started hammering it in , of course nothing happened , so on to more drastic and barbarian methods.

This manifold has two large ears that stick out where the exhaust pipe mounts up with dowel pins, with a large ball peen hammer I started wailing on the manifold ears , finally I saw it move and that's when I knew it was my b!tch !

Notice the cylinder stud is still in there, it either has to be taken apart of cut off to get it out of the cylinder .

I am going to get some Kroil and start soaking the exhaust studs with it every day or so and see if it will break the corrosion around them down a bit.

After that most likely I will weld nuts to them with the arc welder and try to remove them.

 

[Big Kahuna]

A long time ago a buddy had a 650sx. Cannot remember what happened but we pulled the motor. I was going to refresh the top end......... Sounds like you ended up with this motor!!!!!!! LOL. I could not even get the head off. Much less the cylinders. I think I got the exhaust manifold off............. He ended up buying a newer used 650 from Dunnavant Performance.........

 

[WFO Speedracer]

Dunnavant performance, there is a name I haven't heard in years , I used to do a lot of business with Brian before he got shady as hell.

Back around 99 - early 2000's , when I first went into business for myself.

When salt water corrosion builds up around the studs there isn't much you can do , Hot products used to make a special head puller that screwed into the plug holes and rested against the studs to pull the 650 - 750 heads off with , not sure if they still sell them or not.