KZ750 Beginning progress... (PICTURE HEAVY)

[akcender]

Alright, heres what happened. I was a foolish teenager that didnt really know anything about bikes other than they had 2 wheels and an engine. For some, this seems to be enough to start on a a project and for a while i was one of those people. This all changed after disassembling the engine from my 1976 Kawasaki KZ750 which, i must say, was (and still is) in immaculate condition. After i split the cases, i was hit with a realization that i really didnt know anything about bikes. So much so, i threw out the kickstart spring guide thinking it was an electrical conduit connector (my first and hopefully my last stupid mistake). This led to reading everything i could find about the bike over the winter months so i could competently re-assemble this engine. Now that i have started the re-assembly process i am finding that it really is quite simple, but, i am very glad i took the time to read up on how this thing goes back together. Well, after reading that over again im not sure why im telling you all this but anyway, heres some pictures from last summer and some new ones.


Here shes sits after i bought her

You all know whats going on here

My very tight workspace (though i am very grateful for it, thanks dad!)

Just before i pulled the engine (I did this alone, i was 16 at the time, i absolutely destroyed my back. Please, do yourselves a favor and get help when you need it.)

There was some rusting in the cylinders, nothing major, just on the surface. Planning on honing them right after i get the bottom end back together. If there is any damage due to the rust, i have full access to a machine shop and i plan to bore it over to the next dimension up.

Now for some updated pictures

Dry fit of the cases, i had applied the gasket and planned on scrubbing them by hand but i then decided to further strip them down and soda blast them. Sorry for the crappy cell pics, ill get better ones when i start blasting.

And just one last one to show off what you can find in Toronto...

 

[Nebr_Rex]

Re: KZ750 Beginning progress...

Measure your bore.
The 0.50 stamped on the piston means 1/2 mm over already.
Also I have a request.
If you get into the engine far enough to remove the valves from the head.
Could you get an accurate measurement of the valve head diameter,stem diameter and length.
The KZ750 twin uses a large odd sized valve shim not used on any other KZ and is difficult to locate.
And I was thinking if the oversized(head dial. only) KZ1000 valve would work.
That along with an aluminum sleeve in the lifter bore so the 650 - 1100 buckets can be used.
And for pistons.
That KZ750t uses a 19 mm pin, the standard KZ1000 uses a 17 mm pin.
If you would also measure the piston from the wrist pin bore to the top side where it starts to angle in at about a 45° going up to the very top of the piston.
If that measurement is close to that 1000 or 'j' model it would give people a larger selection over size wise and a choice between dome heights.
I would have done it by now but I'm unable to locate one locally.

 

[akcender]

Re: KZ750 Beginning progress...

Ill keep all that in mind when i get to the top end. I was wondering what the stampings meant, sweet i already have an over bore! I can tell someone really liked this engine, very well maintained. It might be a while till i can get those measurements to you, if you think i have forgotten feel free to remind me later on.

 

[akcender]

Progress today,

Starting removing parts, lots of pictures to reference back to for re-assembly.

What my small workspace has turned into...

 

[akcender]

More disassembly today, also had the first mishap.

Removed cam chain tensioner mount

Removed crankcase breather assembly, here comes the mishap...

When removing what i assume is an oil guard for the breather system, one of the bolts broke flush with the surface

So, i guess its time to ask about removing broken bolts from inside an engine. Anyone...Anyone...

 

[Nebr_Rex]

Does your local welding shop have a tig?
First, clean the corrosion off the thread area with something like a dental prick.
This will give you a better weld.
Second, weld a washer to the stuck bolt.
Use a washer with a smaller hole than the bolt.
Use a larger washer on top of that if needed.
Better control of the weld with a shallow hole than the deeper one of a nut.
Then weld a nut to the top of the washer(s).
Let cool to room temp. and start working it back and forth.

 

[john83]

Or go buy an easy out set.

 

[ronnie]

Definitely use an Easy-Out.. They work. It comes with drill bits and easy out bits... You drill a hole in the center of that broken bolt(use a center punch and hammer to make a divot in the center for the drill bit to catch) then you use an easy out and a wrench..

Also, before you do all this, spray some PB Blaster penetrating oil to loosen it up a bit. If its still stubborn and the easy out is having a hard time, get a propane torch and heat up the metal around the bolt to loose it up too.

 

[akcender]

Definitely use an Easy-Out.. They work. It comes with drill bits and easy out bits... You drill a hole in the center of that broken bolt(use a center punch and hammer to make a divot in the center for the drill bit to catch) then you use an easy out and a wrench..

Also, before you do all this, spray some PB Blaster penetrating oil to loosen it up a bit. If its still stubborn and the easy out is having a hard time, get a propane torch and heat up the metal around the bolt to loose it up too.

Im in the process of removing it right now, i chose the easy out method. It's been sitting with penetrating oil over night and i will keep spraying it periodically during the day. I just want to start soda blasting!!

 

[akcender]

Easy out was a no go. Had to drill and tap it again. I think it turned out alright. Im very glad that it is not a very critical bolt, the repair should work just fine for what it is.

Picked up some ZEP Calcium Lime Rust yesterday and threw my case bolts in some. The results really are amazing, clean as a whisle.

Got the cases fully stripped and ready to go.

Soda blasting coming soon!!

 

[john83]

I had an exhaust bolt like that once. Tried everything and just couldn't get it. Ended up doing the same thing, drilling it out and putting a Helicoil in it.

 

[Nebr_Rex]

Or go buy an easy out set.

Bless your heart.

 

[akcender]

Ive moved this thread over to the Engines section where i think it is more relevant. If anyone is following it be sure to check it out over there.