How to hook up vacuum gage?

I usuall will find a spot on the runners and use my own fittings, I think you will get the same results at the PVC also

Thanks. I tried to set idle screws, but didn't get any response from them. I think maybe the choke isn't opening up all the way. Will check that out next!

So where do you do this? PCV line or on back center of intake?

Thanks David. I will try it and see

to add, the vacuum gauge is probably the best tool i own
its easy,and will lead you in the right direction, if you put the vacuum gauge in and it reads 15 inches you know there is a Mechanical problem and changing the plugs, wires, points is not going to help, if low i pull out the compression tester and try to pinpoint where the problem may be, i used one yesterday on an overheating problem, impeller was intact and i know this engine pretty good and told my guy to put a vacuum gauge on it, it read low, then i told him to do a comp test, and i told him number 2 and 3 are low..he said how did know? its like your kids.... you keep track of these things.
if i would of let him, he would be searching all day for the problem.
a vacuum gauge should be in every tool box if you work on this stuff

David....Thats the spot. Look on mine up above. Its the port about six inches or so away from the rear of the carb. I don't recall noticing the little holes in mine though. Not sure that makes any difference.

I just bought a brass nipple at the hardware store. I also had to get two different sized hoses. One to fit the vacuum gauge, and one to fit the brass nipple. You can buy little plastic "step-down" connectors to connect the two hoses together.

Thanks.
That's what I figured. Also not sure what's up with the two holes but I'm sure it will be fine.

I stopped by ACE on the way to work and got a brass fitting that works.

Anybody have a resource on vacuum testing procedures? What the readings tell you etc.?

I found some stuff on the web but I'm sure the folks here are much more knowledgeable.

David.....Just hook that pup up and turn the motor on (at least thats what I do). In fact, I have my gauge hooked up permanently in my truck. I think its the best way to tell what your engine is actually doing.

You can start to adjust your idle mixture screws, timing, etc, to see what it does to the readings. I like to have the idle set around 650-750 rpm or so to get a solid reading. If you rev the motor up, the readings will go up.

I am interested in seeing what types of readings Eric likes to see, and what rpm range. He knows A LOT more than the internet!! In fact, I think he invented the internet. No wait, that was Al Gore.

Check this link out guys. A good overview on vacuum readings.

http://www.classictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm

85jws wrote: Alan, I see that in your pic you just have a cap on the brass fitting. Can you run like that? Do you leave that fitting in there all the time?

Thats just an automotive vacuum plug from any parts store, it runs like that and the fitting stays in permanently

i like to see 18 or so on bone stock low hour engines, alot of things will change vacuum, a hot cam will, a stretched chain, leaky valves all mechanical things...i just use it as a guide to send me in the right direction, if low i will then do a comp test...consider them like a blood pressure test and checking your pulse