Where we left things in the last instalment was that I’d made some attempts to learn to tune the Webers, a task made somewhat harder by the discovery that the engine might be in a somewhat more hardcore level of tune that I’d bargained for.
But for the first time in weeks the Hakosuka came down off the axle stands, and at least it looks good (even if it doesn’t go)!
First I had another go at the carbs, and actually got a pretty decent result after a bit of experimentation. Basically what you do, is adjust the low-rpm mixtures until you optimise them (listen for the point where the idle is highest).
Then you use this device to measure the amount of airflow going into each carb. There’s a plastic cone at the end of the white tube, and when you stick it in the carb airhorn, a little pellet rises up that orange tube. The higher it goes, the greater the airflow. You adjust the idle speed screws on the carbs until the airflow is all the same.
The result was this:
As you can see, it’s reasonably smooth, but the idle’s a bit fast, it’s a bit slow to return to idle when revved, and when you shut it off, it runs on (called dieseling) somewhat. What I think I did wrong was set the idle speed with the linkages attached. I’d loosened the linkage arms on the main throttle jackshaft (so that adjusting one carb wouldn’t affect the others) but I think the weight or stiction of the heim joints of the linkages were holding the throttles of one carb open a hair….and so when I adjusted the other carbs to match it, it all ended up too fast.
And also I think the main return spring for the throttle linkage was too weak, and not forcing the carbs closed properly. So I decided to tighten the spring tension when PA-TING! The spring retaining bolt broke! Ahh well…easy enough to get a new one.
Oh, by the way, before I tuned the car last I replaced the distributor cap and rotor:
I guess it’s one of those things…on new cars with cam angle sensors and coil on plug ignition, these parts don’t exist. I’d just forgottten that on old cars these are regular maintenance items. Replacing the worn old ones made a big difference in smoothness:
But since the engine was warmed up I did an oil change, and one of the goodies I discovered was this extended sump. It holds 8L, which means that an oil change involves two cans of oil and two drain pans!
But remember that wobbly throttle pedal? I’d made an attempt to fix it but it was still a tiny bit wobbly. So I made a bridge: a short strip of thick steel to bridge over the uneven firewall surface and provide a flat surface for the pedal to bolt to. Success! It’s rock solid now.
The brake mastercyl arrived too. Chatswood Brake and Clutch bored it out and inserted a stainless steel sleeve, then fitted new modern seals (which required some machining). Expensive but worth it, the brakes feel good. One unique feature of the Hako mastercyl however is that you have to bleed the master cylinder after installation. Weird.
So far, we’d done pretty ok. I’d broken a component on the carb linkage, but it was easy enough to source a new one, the car now had brakes, and I was looking forward to having another go at tuning the carbs. I had a couple of days to wait for the new part to come in, so I decided to have a look over the electrics.
…and that’s when we hit a snag.
First, the headlights didn’t work. So I start at the beginning, and trace the +ve wire from the battery to this block of fusible links…which helpfully has “HEAD(L)” and “HEAD(R)” on it. So I wiggle some wires, and when I wiggle the orange one (which is NOT for the headlights), the headlights come on!
Um…alrighty then. Then I replaced some blown fuses and everything went haywire….put on the hazard lights: headlights will come on (but hazards won’t). Put on the park lights: headlights will come on (but park lights won’t). Press the brake pedal: headlights will come on (but brake lights won’t). Turn the headlight switch: nothing….go back under the bonnet and wiggle the fusible link block again: somewhat returns to normal but indicators don’t work. And hi-beams don’t work.
So I take off the dashcluster to have a look behind and the surprise was that the wiring is very hacked-up…there are vampire taps (with cut off wires) everywhere, and lots of wiring has been re-routed to different things…the most bizarre thing is that there is a wire tapped into the instrument lighting that goes to the front of the car….I suspect that some genius decided to use it to trigger the headlight relay (maybe the headlight stalk is broken)…and if the headlight switch is somehow bypassed then it might explain why hi-beam doesn’t work.
Oh dear…well, this is pretty much the limit for me. I’m okay at taking apart the oily bits but I can’t even figure out how to use a multimeter. So I think the next step will be to get an electrician over to spend maybe a whole day on the car cleaning up things. Will be expensive but if it fixes the electrics for good and is reliable, then it’ll be worth it. Some amateur MacGuyver has been at work butchering the electrics, so getting it sorted properly will be a priority…if only to avoid the embarassing scene at the engineer when they ask me to test the brake lights and the headlights come on instead.
A few weeks ago I said that when buying old cars, it’s better to buy a car that’s in regular use, rather than a car that’s been lying idle, like mine has. Maybe I should start taking my own advice! But I think we’re close…very close to getting the car nice and solid for the road….anyone know a gifted auto electrician in Sydney?