Top end is together now, carbs installed, points gapped & static-timed. OK, so lets do a simple crank test. Turn the ignition switch on and... nothing. Whole bike dead. Inert. Still in a 35+ year sleep even after being thoroughly jostled, shaken & de-/ re-constructed.
Long story short, the rotary contacts inside the OEM ignition switch were electrically open, even though to the naked eye they looked clean & good. An invisible film of oxidation. Not long after disassemble/clean/reassemble of the ignition switch, we discovered the same problem with the dimmer switch contacts that was preventing the headlight from energizing; looked good but, just would not pass current. In all cases, a gentle application of a miniature Dremel wire wheel polished the flat contacts to a fine bright brass sheen, and a few swipes of 2,000 grit wet-dry abrasive paper on the rotary contact points resolved the issues. In both cases, lesson learned; test before install
. We'd completely disassembled the handlebar switchgear months ago to replace the sleeves, and simple cleaning at that time of what looked like clean contacts would have saved us a day of re-tracing our steps & circuit troubleshooting. A thin wipe of conductive grease on the now-cleaned contacts will maintain good conductivity likely long after we've left this world for those great twisty roads in the sky.
So now we have a sound electrical system, everything works, and a simple test crank moved the crank, pistons & tranny under power of the starter motor for the first time in 35+ years. Nothing smoked, melted or blew up
.
Moving right along, the petcock handle was, shall we say, reluctant to move when we got the bike.
Penetrating potions, heat & gentle persuasion had done nothing to change that for the last 18 months or so. One more trip to the wash tank, dig more crud out of the screen area, and into the ultrasonic tank filled with the Yamaha Carb Dip solution for a total run time of about six hours. Heated the solution to ~70 deg. C (~160 deg F.) for the duration. VoilĂ ! The handle finally freed enough to be removed.
The petcock is the later version of the 'early' black petcock that has an O-ring on the handle. The earliest petcock handles sans O-ring had an unfortunate habit of leaking the contents of the tank into whatever environment it was located at the time. The original handle O-ring came off in brittle pieces upon removal. The rubber sleeve seems undamaged and is surprisingly pliable. The valve portion of the handle exhibits the same pitting from corrosion that is present on any bare aluminum that was exposed to atmosphere during it's long barn sleep. We had a NOS K&L petcock rebuild kit on the shelf for decades, as we only run later petcocks that have a tapered nylon cone valve & never needed it, so it was consumed in the rebuilding of this petcock.
Red arrow shows groove for the O-ring introduced not long after production commenced. The red square shows the pitting.
A trip into the blast cabinet for some cleaning, and it's ready to reassemble. The bottom brass filter screen is present & undamaged - we just forgot to include it in the pic.
After fresh O-rings, a dab of silicone grease on the handle valve and inside of the rubber valve sleeve, and it moves smoothly with normal resistance. Bench test shows it's liquid tight. Ready to install.
We've had a mismatched set (mix of Z1 and '76 KZ900) of OEM 4-4 pipes with baffles hanging in the shop for a year or so that were always planned for this bike. They show a few small dings, some tiny rust/pitting spots here & there & a little discoloration at the bend of the head pipes. No road rash. Considering that we paid well under half the cost of a repop set for them, they're fitting for this bike. They maintain the concept perfectly that was our intent from the beginning; that of a refurbished-original 'suvivor' that's correct at a glance from ten feet. We installed the pipes yesterday. The Lovely Z1BEBE was again instrumental in assisting with this bike, as she spent most of the morning cleaning & polishing the pipes. She then helped corral the pipes during installation, keeping them together at the rear, inserting the mounting bolt and generally maintaining things under control while slmjim got the headers into the exhaust ports with the split keepers taped in place and the exhaust collars attached. A 4-4 install is a challenge for one person 'cause there's so many moving parts spaced far apart. Besides, she makes the shop prettier
.
In three days when the weather is expected to cool:
Hook up the timing light & dwell meter, DMM to monitor charging system, mercury sticks on the carbs, hang the aux fuel tank, place a fire extinguisher on each side of the service bay, stretch socks over the ends of the pipes to keep the inevitable carbon bits from blowing out & trashing the shop floor for ten feet, place a box fan in front of the motor for cooling and, set up the big 1/2 horse exhaust fan at the basement door with the upstairs windows open so we don't gas the entire house, ourselves and the dogs, and do the first test start & fine tuning.
Anticipation...!
Until then, we work on cleaning the bottom inch or so of the tank. Looks like light rust with maybe some varnish. Not sure about the varnish - it's only on the left rear side that was the down side while the bike was on the sidestand for years & is very difficult to see clearly. First up on that; a half gallon of kerosene along with half pound of nuts. Shaken, not stirred (Bond... James bond
) & see what happens.
Good Ridin'
slmjim & Z1BEBE