KZ700 Cylinder Head help

Hello everyone. In somewhat of a dilema. Long story short. One of my exhaust studs was broke when I purchased bike. Po had hillbilly rigged it with jb weld and a bolt. Did not even see it when looking at bike. Basically I tried multiple things to cure and exhaust leak but honestly I think the chunk that is missing is what is leaking. Bike backfires at high rpm pretty bad. I am able to get a head off of ebay, but am very nervous about replacement. I have a clymers manual but I do not feel it goes into detail enough. If I were to do this myself and replace head how much work am I looking at? If I were to go the route of having a shop fix what kind of money would Ispend? Also what new seals and parts do I need to buy? Thanks

Pics.
Need to see what the problem is.
Have you checked compression? The head might be worth fixing while on the bike.
If not, have the seats and valves done,no need on installing a head with leaking valves.
Get a gasket set, it should have all the seals you'll need.
Set the valve lash on the bench, don't wait till it's on the engine.
Once installed with new carb boots, run the engine till warm,let cool then retorque head at 30 ft. lbs.
Do this several times and put a little oil on the threads.
And be very carefully them 6mm cam cap bolts, do not over torque them.

This is the mess I am dealing with. There was jb weld and red sealer all over. You can see where the bolt snapped inside. From my understanding the casting broke and they crammed a bolt in there and it snapped. Do you think a machine shop could fix something like this?

A machine shop can fix it if they are fully equipped. They may need to build the area up with some weld and re-drill and tap the hole after removing the broken bolt, but they should be able to do this. Ed

Would I need to remove head? It is the outter most bolt

The correct way would be to remove the head and have machine shop weld then drill, tap, then insert either a heli coil or other type of insert into the tapped hole. You can then put a stud back in. The second option would be (if you can find someone) is to remove the broken stud, weld up the area then heli coil it.

Going to take to a machine shop tuesday and see what they say.

IMO a competent mechanic can probably fix that without removing the head. There's a good surface to center punch and drill on that broken stud. It's outboard where it can be reached easily. Good drill bits, a butane torch, can of liquid wrench, good ez out & a steady hand are mainly what's required.

Use a spring loaded center punch. Nail that stud dead enter with it. Start with a small bit & work your way up. When you have it drilled out 50%, put the heat to it, then spray it with the liquid wrench and let it work. Make sure you shake the can up good first. Drill completely through the end of the stud.

I dont' care what anybody says. I've used every imaginable penetrating oil there is, liquid wrench is available off the shelf just about everywhere and works great.

If you are diligent and patient, you can get that stud out and save yourself a considerable amount of money.

Its not the bolt that's problematic. Its the casting is broken also. Going to a highly recommended welder tomorrow. Is there anything I should know about welding on bike? Undo battery?

Do as you wish. I'm saying that from what I can see in the picture, you probably don't need to weld anything or take the head off the bike. There's enough meat left to install a new stud or even a bolt for that matter. That is fixable on the bike in less than 1 hours time.

undo the battery.
put the ground as close to the weld area as possible.

leon

Going to have a welder take a look at it tomorrow. See what they say.