2 kz750 barn finds

found a 76 and 78 KZ750 on craigslist and brought them home. Mileage on both says its in the 20k's. The engine only turns on one and of course its the one without a title . Looking forward to getting at least one of these back on the road. There will be a lot of learning involved here for me which I'm exctited about. Had tons of bike over the years but have yet to have to do any engine work besides basic carb cleaning etc.... Body work I can handle. Repair manual in the mail. Goal is to get that other engine unlocked! Also need to buy a carb since both have none. Stock or is there a newer better option?
I have it sitting with a bunch of pb blaster sprayed in the spark plug holes right now. 2 days and nothing still. But thats just trying to kick it too. I've heard something about the stator locking up the engines. I'll start googling that.

Thanks!

Welcome aboard. Here's something you need to know before working on your KZs:

Do not even try to use Phillips screwdrivers on the Kawasaki cross head screws. Despite their appearance they are not Phillips screws. They are Japanese Industrial Standard (JIS) screws. The tips of Phillips screwdrivers are too long & pointed to allow the 4 blades of the screwdriver to properly engage the screws, so when you apply force the screw head slots will deform and look like crap. The fact is that Phillips screws were deliberately designed to have the screwdriver bit "cam out." This was done to prevent production line assembly from over-tightening, stripping, or breaking the screws. JIS screws do not have this problem. A proper fitting JIS bit can tighten a JIS screw to and beyond the torque spec without camming out. Here's the good news - you can easily modify standard Phillips screwdriver tips to fit the JIS screws.

I have ground down the tips of DeWalt #2 and DeWalt #3 Phillips to make them fit JIS screws. The large crosshead screws on the cases take modified #3 bits (or genuine #3 JIS bits). To modify the DeWalt bits you need to grind the very tip a little, then test fit, then grind a little more and test fit, etc. until the bit no longer "rocks" back and forth in the screwhead. Picture 1 below shows how a DeWalt #3 bit fits the case screws of my KZ650 after being ground properly. The #2 DeWalt bits can be modified the same way to fit smaller JIS screws. Pictures 2 and 3 below shows DeWalt #2 and #3 modified bits.

I did find a place that sells authentic JIS bits. They don't list the #3 bit, but if you contact them they can provide the #3 JIS bits even though they are not listed on the website. These folks were very easy to work with, and the authentic bits do work great. Here's their site:

www.rjrcooltools.com/shop_item_detail.cfm?subcat_ID=89

Pictures 4 & 5 below show a comparison between my home made modified bits with the authentic JIS bits.

PICTURE 1

PICTURE 2

PICTURE 3

PICTURE 4

PICTURE 5

thanks Ed. I will invest in some. Anyone have advise on where to start regarding the locked engine? I have no idea what I'm looking at regarding the stator clutch.

A locked engine usually means the cylinder liners and pistons are corroded. This is particularly true if the carbs are off and air/moisture has a direct path into the engine. Hopefully the PB Blaster will loosen things up, and doubly hoping you don't have a deep pit in the liner where the rings were parked.

Good luck

Quote: "But thats just trying to kick it too"
Doubtless, someone more knowlegible than myself will correct me if I am wrong, (not sure about the twins) , but my 650 has a 17mm fitting under the points cover ( on right side ) for use in rotating the engine during servicing...If has a smaller outer bolt, it is to hold the timing plate/advancer assembly in...DON'T USE THAT ONE TO TURN THE ENGINE! Use the inner/larger one...17mm socket & a breaker bar might afford one, more (and more controllable) torque to break it loose...Let 'er soak....PB Blaster is your friend! I'm with Nessism, wishing you luck on the cylinder scarring... ;o)

thanks,I'll try it tonight. Appreciate the help.

Yeehaw its loose! Pb blaster for 3 days and then real easy on breaker bar. After it loosened it I can now kick it freely too. Pretty optimistic. Now just need a carb.

I have a set around here somewhere! where ya at?? I'll look for um !

Don't get too excited just yet! I'd pour some oil down the spark plug holes and loosin up the rings How long has it been sittin?
Marval mystery oil whatever ya have?? Work it into her good!! Turn it over by hand!

I have no idea how long. I'd suspect 10 years possibly. In a garage though since there is very little rust. I'll continue to loosen it up every day and put some marvel mystery or tranny fluid down there for now. I won't have the carbs mailed and installed for a week or so anyway. Crossing my fingers but its feeling promising. I'm looking for a 70ish carb. Ones a 76 and the other a 78. Both 750b's. Thanks