Regular readers (if anyone who reads this endless chain of Kawasaki Z1 resurrection stories can be called Regular) will recall the broken intake manifold screw problem. I tried soaking the busted screw in penetrating oil, drilling it and using an easy-out to no avail. I heated the cylinder head around the broken screw. It didn’t budge (the screw, that is). I even ground a Harbor Freight screwdriver into a straight-sided, square easy out so as to not expand the screw tighter into the hole like commercial, spiral-type easy outs. I had a really good purchase on the thing but nothing doing. The screw was well and truly stuck.
My last resort hinged on drilling a hole exactly through the center of the broken piece with a left-hand drill bit. If you’ve never used a left-hand drill bit they are exactly like a right-hand drill bit but they cut in an anti-clockwise direction.
The reason lefty bits are the nads for removing stuck or broken bolts is because of their natural tendency to unscrew whatever they are drilling into. By increasing the bit size in stages hopefully you can get the offending screw so thin that the remaining threads weaken, collapse slightly and wind out of the hole looking like a coil spring. And that’s mostly what happened except the thread came out in pieces.
After clearing out the swarf I ran a bottoming tap into the hole and tidied up the threads as much as possible. I will use a slightly longer screw to compensate for the compromised hole but I’m pretty sure it will be fine and I have avoided using a Helicoil thread repair, which is the hack mechanic’s favorite crutch.
Zed was missing a few ignition parts so my Internet buddy Skip Duke sent me a spark advancer that very nearly fit the Kawasaki. The bolt that holds the advance to the crankshaft was a size too large for the hole in the advancer. Skip and I held a web-confab and decided that the advancer was the wrong part. Skip dug around his Z1 parts horde and found another unit that will work. This is the best thing about the Internet: you meet generous people that share your old motorcycle affliction.
I haven’t forgotten about the carburetors either. I’ve been soaking them in Evapor-rust and the stuff is doing a fine job. It’s very mild so you can leave zinc carb bodies immersed for days without fear of eating away the good parts. All four of the carbs are clean and I’m waiting on a few parts before I can reassemble the rack.
Zed’s little clutch-cover, oil level window was black with sitting-bike mung. It was so black the oil level could not be determined. I removed the cover and cleaned out behind the metal back-plate. Since I had the cover off I figured it would be a good idea to check the clutch plates for wear. The fibers are within tolerance and the steels are only slightly rusty so I’ll clean all those parts up and Zed should have a functioning clutch.
When Kawasaki designed the Z1 they went all out. This was Big K’s flagship motorcycle and the robust clutch is a fine example of strength. The large, straight-cut clutch gear would not look out of place in a one-ton manual truck transmission. The fingers that locate the fiber plates are surrounded by a steel band to prevent them from spreading under load. This clutch is awe-inspiring and looks like it could handle double the Z1’s 82 (claimed) horsepower. The bike has 41,000 miles showing on the clock and the metal parts show minimal wear. I am impressed.
Don’t take my word for it, here is the author of the Z1 repair manual waxing eloquent over the Z’s clutch.
I’m making another list of parts and will be blowing more money on Zed. I really hope this engine runs without a lot of knocking and the transmission shifts like butter.
I drilled the screw in stages until I could try my handy-dandy left-hand drill/remover tool.
The broken screw is small, like a 4mm, maybe a 6mm and there’s not a lot of room for error. The little extractor tool had a good bite into the screw but the thing would not budge. One thing you don’t want to do is break off an easy out because they are super hard material. There’s no drilling the things and you are well and truly screwed if you manage to get the hole full of busted tool steel. I eased off. Sometimes you make more progress doing nothing rather than doing the wrong thing.
Admitting defeat today I decided to step away from the cylinder head and give the hole a few more days soaking with penetrating oil now that I can get to the backside of the situation. In addition to soaking I’ll heat-cycle the aluminum with a 1500-watt heat gun in the hopes of disrupting the steel screw/aluminum head interface. I guess the worse case would be to drill the thing all the way out and use a thread repair insert but I really don’t want to do that. That would be true hackery.
A complete 
Included in the order was an O-ring for the re-sized drain plug and the washer that goes between the oil filter and the oil filter spring. With these parts I managed to get the bottom of the engine buttoned up. Progress has been fitful but Zed is getting closer. I’m really jonesing for concrete so I may have to pull off Zed and pour a yard to keep my soul on ice.
My idealized, simple douche with carb spray has turned into a complete tear down of the 4-carb bank. I haven’t counted but there must be well over 100 parts between the set. Cleaning the white, calcareous deposit liberally coating the inside of the float chamber has kept me occupied and humble.
Parts for Zed have begun to trickle into Tinfiny Ranch’s high altitude motorcycle shop. I scored four new intake rubbers for $50 off of Ebay, which seemed like a good deal to me. Not such a good Ebay deal was the ignition advancer bolt and grooved washer. I paid $19 and later found the two parts on Z1 Enterprises for $13.
Z1 Enterprises has a lot of Kawasaki Z1 parts for not unreasonable prices. I bought a complete new wiring harness for $139. The harness comes with the main wiring loom, the gauge cluster loom, the rear tail light/blinker loom and the loom underneath the battery box that the regulator, stator, main harness and some other junk I can’t remember plug into.
I’m into Zed’s resurrection for about $240 so far. I’ll be going back to carb cleaning now. The things are a mess and every time they dry out a new, white-powder film appears. I’m using mild solvents so far but I may have to step up my game to get the carbs spic and span. You know the routine; Part 4 to follow.