Vacuum at TB

[pomm001]

Evening
does anyone happen to know the range of vacuum expected at the TB under normal testing?

I have been given a couple of expensive SMC digital vaccum gauges and wondered if i could use them to set up my TB's next time

The gauge range is max -760 mmhg which is appox 30 " hg ?
I guess that only someone who use a tradition gauge would know this one

thanks

 

[Timolgra]

It's around 0.3 bar which I'll leave you to convert

 

[Flipfly]

It's around 0.3 bar which I'll leave you to convert

Is this any use http://www.hero.ca/heropdf/quickref/PRESSUREQR.PDF

 

[Steptoe]

It doesn't matter what the vacuum is, you don't set them to a precise vacuum.

Just so long as they're even.

One mans vacuum is another mans hoover

 

[Timolgra]

It doesn't matter what the vacuum is, you don't set them to a precise vacuum.

Just so long as they're even.

One mans vacuum is another mans hoover

I think he wants to know if the range of his guages are suitable

 

[(RIP) Kaister]

digital vacuum gauges will be next to useless, i'm afraid.

unless they represent an analogue display - say an led bar graph

just having numbers will be unreadable cos they'll fluctuate too much.

You need needles or levels

 

[Steptoe]

I think he wants to know if the range of his guages are suitable

Call me old fashioned, but why not just plug them in and find out

 

[Seamaster]

On the few pictures that I have seen of Motomartins bike I noticed that the TBs are connected with a tube, does this do anything or is it a wind up?

 

[Jon P]

American ones are joined together with a tube - the combined vacum in the tube is then used to operate the charcoal cannister that the US have to have to meet the EPA requirements in California.

 

[Timolgra]

Call me old fashioned, but why not just plug them in and find out

You're old fashioned

 

[(RIP) Kaister]

On the few pictures that I have seen of Motomartins bike I noticed that the TBs are connected with a tube, does this do anything or is it a wind up?

theoretically, its to do with evening out pressure pulses at low revs and improving the driveability.
It does seem to do this - mine is really smooth at low revs - but then i've also taken a lot of time to balance the throttles using a home made manometer.

I haven't experimented with different diameters of tube yet.

 

[pomm001]

Thanks for the replies ,it looks as if the gauges will work OK
so will just have a go and see,not expecting too much, just the thought of being given something that may be of use has got the better of me,stll looking out for a mercury manometer