'73 hightop bus adventures
Posted: Wed Apr 08, 2015 12:00 am
Hi all,
A few weeks ago a young gentleman contacted me on Instagram (a photo sharing service) since he saw I was nearby and his clutch wasn't coming back up. He replaced his cable and I never thought much of it, until this weekend when he contacted me again saying his bus won't start. Being in the area today, I went and took a look.
"So what happens when you try to start it?"
"Well I turn the key and the oil light gets dim."
"What about the gen light?"
"What's that?"
Well I dunno 'bout you guys, but on my planet, even the good German alternators need a bit of current to excite the windings. So I politely ask how many miles are on this "new battery."
"About 200."
"Why did you replace the old one?"
"It died at about 200 miles."
"And you never saw the gen light come on?"
"Never seen it ever."
This poor bus. I can't even begin to look for wiring anomalies; there are random spade terminals everywhere, missing breather hoses, and the central idling intake hose is flapping around by the #3 spark plug boot. Getting my zen on, I approached the problem one step at a time. Somewhere between mumbling about the need to filter ALL intake air and the need to not burn the bus down with unfused wires, I found 12v at the idiot light, and one of those damn Bentley wiring diagrams without the little pictures for Luddites like me. After finding out that the alternator harness has a simple connector into the… Well it should go into the voltage regulator, but it certainly looks like it's going nicely into this void in the engine tin…
"Did the gen light go on?"
"This "G" light? Never seen that before!"
So the battery has enough juice to operate the idiot lights, but the second we try to start it they still go dim. No matter, I have this superior German generator that keeps it's elephant-memory-residual-magnetism. This is the third bus I've jumped since building the new engine. (Math game: If I continue at this rate, I'll have jumped 600 air-cooled Volkswagens by rebuild time. )
At this point, I must summon excitement and concentration to massage these factory dual carbs into synchronicity, because this engine is barely hanging in there on two cylinders even with my hand guiding the throttle bar. We let it stall out so I can check cutoffs and choke participation. Checking each idle cutoff solenoid revealed left and right clicks, with the CIC solenoid down for the count. No matter, says I, as I calmly unscrew it to replace it with… Oh, it's been beheaded. Lovely. Good thing, because I don't actually have a spare with me anyway…
Hack the CIC inlet nipple back into the left carb, (it was hanging out by the VIN number stamp,) get the red Gates vacuum hose connected back up to it, reinstall the Headless Horsevalve, and fire it up. No change, so let's see how the CIC adjustment is playing in right now…
Ah. The large central idling volume (speed?) screw is bottomed out. Finger test revealed that NO air was getting through. Out about two turns it goes, and WOW the engine responds better! Now we're on to something. Daylight was essentially gone at this point, and my snail gauge was at home, so my Uni-Ears went up to bat and I hacked my way through the dual carb idle adjustment procedure, noting EVERY change I made so I could reverse all if necessary.
Test drive notes include two jaws on the floor: Me, thinking, "holy shit that actually worked," and the owner's wondering how something free could make it drive so much better. Oh, and the right choke was adjusted almost 90* too closed, so it was on choke for the last 400 miles. That really smoothed out warm up and test driving.
The kicker?
A receipt from a local garage for $1,400, itemized including five hours spent "tuning and optimizing carburetors." Not only was the CIS completely bypassed, but they left hoses off, bare wires laying down, the alternator unplugged, and adjusted the idle at the carbs to hit 700 and stay there, warm or cold. Yeah they put in new points and plugs, (with #s 2 and 4 extension leads on #s 1 and 3 as well,) and changed the oil, but I really think they did more harm than good. THIS is why people buy mediocre carbs for $700. THIS is why these cars can acquire a bad reputation with spouses, neighbors, and the public. I'm speaking with the shop on Friday.
May this bus live to see many more roads,
Robbie
(So what if I was preoccupied at the time and I stole these pictures from his gallery. Same bus…)
PS- I'm going back soon with the right tools and more time to adjust the carbs properly for high speed sync and idle sync. There's still some decel backfiring, though power is smooth and consistent through the RPM range cold and warm now.
PPS- Airhead parts sold me two clutch cables that were too short last year. This bus has a cable that is too long, so every gear grinds. From where? Airhead parts, of course. They hung up on me twice last time, saying the cables were too old for them to do anything about. Well this one's fresh. And I'm out for blood.