Vacuum guage

[Guest Ken8143]

Some older vintage vehicles had a vacuum guage. What was the purpose of that?

Any merit to having a vacuum guage on the scoot?

[Marcarl]

The vaccum gauge gave you an indication of the amount of fuel you were using. The vaccum was taken directly from the intake manifold, and the more vaccum you could maintain the better for fuel.

Some other brands also used vaccum for things such as windshield wipers and so it was kind of handie to have a visual on the available vaccum. These vehicles would have had a vaccum tank and so then the gauge was hooked to the tank.

Let's see how right I am when some of the old gezzers jump in with all the real facts.

Carl

[Carbon_One]

That's a pretty good descricption there Carl. Another possible reason for a vacuum gauge would be to monitor the vacuum for a cruise control resvoir. I've installed several AudioVox units on other make bikes and they all needed a tank to hold the vacuum. Never did put a gauge on one thou.

Larry

[ctraylor]

I can remember when I was a kid and the school bus we rode had vacuum wipers. Every time he went up a hill the wipers would stop until we crested the hill.

[Texaskid]

I believe that in the late 60's or the early 70's Pontiac had one installed in the consoles so that you could

judge how much vacuum you were pulling so that you could get the best mileage. The least vacuum the more gas you were burning. Also you could use it to set your mixture on the carb.

[Midrsv]

The only vacuum gauge I remember seeing was in my dad's '65 Chevy Impala SS. It was about a 4" diameter gauge built into the dash and I would watch it drop to near zero when he would kick it. I would love to have that car today.

 

Dennis

[saddlebum]

They were gauges installed at the factory in some cars and were called motor minders. The main purpose at the time was for a driver to be able to conserve fuel by watching the gauge, and keeping the needle in the green zone during acceleration. This would be between 10 and 17 inches of vacume. If you stepped to hard on the gas pedal the guage would drop below 10 inches, indicating that you were using too much gas.

It did however have an added benifit for those with mechanical know how. A person who understood engines could tell what was wrong with an engine based on wether the needle held steady or fluctuated, was abnormally low or high. You would be able to pick out things such as leaking or sticking valves, incorrect ignition timing, intake or vacume leaks and even a restricted exhaust etc..

[dmoff1698]

Chiltons manuals had a troubleshooting section using a vacume gage. It showed you all the readings/movements of the gage and told you what they meant and possible causes.

 

I used to use one all the time.

[Guest Ken8143]

So - is there any advantage to putting on on the bike?

[Squidley]

So - is there any advantage to putting on on the bike?

 

Not really, when you want to twist the throttle it would always tell you that you getting bad fuel mileage

[dmoff1698]

 

Not really, when you want to twist the throttle it would always tell you that you getting bad fuel mileage

 

I would say that depends on how paranoid you are.

 

Like I said, If you know how to read them you can pretty much know all there is to know about the performance of your engine as it is happening. Everything from timing, stickey valves, fuel/air problems to bad driving habits.

 

Since motorcycles don't have a common intake system, you would actually need to install four vacume gages to get the entire picture for each cylinder.

 

Hmmmmm..Can you spell perminately installed Carb Tune? That certainly would be a "different" addition to your bike. But if you are like me, I would be busy watching the gages instead of the traffic around me.

 

Sometimes there is just too much information available. This is a case of Ignorance is bliss!!!

[saddlebum]

So - is there any advantage to putting on on the bike?

I think it would be DANGEROUS. . . An invitatation to watch the guage instead of the road. . .Probably why they quit putting it in the cars. . . .And besides now we have CELL PHONES to kill people.