Comments on: Halloween Cat Blogging

By: Bryan

Bryan — Sat, 08 Nov 2014 05:19:59 +0000

In reply to Badtux.

The SU kit for syncing was two rods that went through holes in the top of the carburetors and then you twiddles with the adjustment screws until the engine would continue to run and the rods were at the same point. If they wouldn’t sync you had to pull them apart and see what was wrong. It didn’t take much to gum them up, and I installed a second filter in the fuel line to be sure that the gas had nothing in it. The car had been in Mexico a few times and you could never be absolutely sure of Pemex fuels, even when you added octane booster. Keeping dust out of anything was impossible.

I understand why the computers are better, but I enjoyed solving the mechanical problems of the old systems.

By: Badtux

Badtux — Sat, 08 Nov 2014 04:53:11 +0000

Four carburetors on a classic inline four Japanese bike, yessiree. Side draft Mikunis feeding individual cylinders from the rear while four pipes evacuated the exhaust from the front. They made four-mercury-indicator carburetor sync tools but I never had one of those (for one thing the mercury scared the bleep outta me), I just had the old fashioned dial type tool where you tried to center it at the zero mark for difference in vacuum between two carbs. So it was twiddle twiddle twiddle… move one vacuum hose… tweak tweak tweak… etc. Then repeat at a higher RPM (use a large O-ring from a Caterpillar hydraulic pump shaft to keep the throttle open by rolling it over the crack between the throttle and the bar end). All the while that the bike was being fed by an IV feed of gasoline from a soda bottle, since the gas tank of course had to be removed to get at the carbs.

Now it’s all computer controlled butterfly valves and individual injectors at the cylinders. No synchronization required, it automatically does it based on the oxygen sensors in the exhaust pipes (since it knows which cylinder’s pulse is passing the sensors at any given time) and mass air sensor in the intake (ditto). All the complexity is in the software in the computer, and software doesn’t rust or corrode — if it works now, it’ll keep working until the computer dies.

Nope, I don’t miss carburetors :).

By: Bryan

Bryan — Fri, 07 Nov 2014 00:25:26 +0000

We must have been posting at the same time, because I missed your OBD-II explanation. It makes sense that California would lead the way and every one else followed. Standards are vital, but it usually takes some outside entity to impose them because the Free Market Fairy doesn’t seem up to the job.

By: Bryan

Bryan — Thu, 06 Nov 2014 03:25:47 +0000

In reply to Badtux.

Never had a float problem on a car, but plenty on lawn mowers and go karts.

Four carbs?! That doesn’t even bear thinking about…

By: Badtux

Badtux — Thu, 06 Nov 2014 03:11:58 +0000

Oh, you can blame California for the standardization. OBD-II is necessary in order to be certified by California’s emissions board to sell cars in California, and standardizes the connector and the command sets. It works so well at monitoring the internals of cars that in some states they don’t even bother with the tail pipe test for emissions anymore, they just plug into the OBD-II connector, note that no readiness indicators show a problem, and you’re good to go.

By: Badtux

Badtux — Thu, 06 Nov 2014 03:09:29 +0000

Float valves getting stuck open. Now that was my “favorite” carburetor experience, the float deciding it was now a not-float and now I have more gas than oil in my crankcase. Removing the float bowl and finding that the float was full of fuel was always a fun experience. Adjusting the float bowl level after you bought a new float was also fun, though not as fun as sync’ing the four carburetors on an inline 4 Kawasaki motorcycle…

I don’t miss carburetors :).

By: Bryan

Bryan — Wed, 05 Nov 2014 21:27:36 +0000

The spam filter freaked because it looked like you were selling something on your first comment. I obviously got it back. I didn’t realize they had standardized and main-streamed the system. When the computerization started you had multiple access connector types and totally different software required for each manufacturer.

Come on, I wouldn’t have known what to do on Saturday mornings in SoCal if I hadn’t had the SU carbs on the MGB to sync. 😉

By: Badtux

Badtux — Wed, 05 Nov 2014 06:21:09 +0000

An OBDII reader is all that’s needed to diagnose most problems with cars today, and you can get one from Amazon.com for $60. No computer or cable required. There are specialized things, like resetting the airbags, that require special computer software, but you wouldn’t be doing that yourself anyhow, your body shop would be doing it as part of the collision repair, paid for by insurance.

Compared to *anything* with a carburetor, modern cars are a piece of cake to repair. Carburetors were a constant misery of vacuum leaks around random shafts and pressed-in fittings, myriad jets that were constantly getting clogged, automatic chokes that didn’t or did too much, and other such hair-pulling nonsense. Meanwhile, if a fuel injector doesn’t work generally the computer will helpfully tell you so and which one it is, pointing at the exact cylinder, thanks to the oxygen sensors and mass air flow sensors and etc., then you replace it and you’re fine again. Same deal if the sensors fail, they’re redundant and the computer has a “limp mode” until you get it fixed. About the only sensor that will cause my Jeep to come to a grinding halt is the crankshaft position sensor, but we Jeepers deal with that by keeping a spare one in our tool box when we’re offroading…

By: Badtux

Badtux — Wed, 05 Nov 2014 05:18:03 +0000

OBDC-II readers cost $60 from Amazon.com and require no software. That’s all that’s required to do most tasks on modern cars. There’s a few tasks that do require additional tools but they’re generally ones that you’ll leave to a specialist anyhow, such as setting the proper pressure in tire low-pressure sensors, which is generally done by tire places when they spool new tires onto wheels. And all that happens if you spoon a tire onto a wheel yourself is that you get an idiot light showing on the dashboard.

By: Bryan

Bryan — Wed, 05 Nov 2014 04:20:04 +0000

The need for the right cable and software, which can be expensive defeats a lot of people who would work on their cars beyond oil changes.

My Honda has six airbags that I know of, and there may be more. I’m not going to be a happy camper if they expand the recall to include my Honda because it will take days to replace them. They will do them one at a time when they have a spare moment, because that’s how the Honda dealer works with recalls.