how to tell if the speedomiter works

[jserb]

just like the title, i have an older speedomiter, and when i blow into it the needle dosent move, im assuming this is a way to check and see if its in working order. its a water pressured guage, does anyone know if its easy to fix or a way to test it to see if it works!?

 

[LubeDude]

Re: how to tell if the speedomiter works

I have know idea what kind of preasure is needed to move the needle, but I dont think you can blow that hard without your eyes popping out.

 

[Chief101]

Re: how to tell if the speedomiter works

you suck.

 

[Pony]

Re: how to tell if the speedomiter works

Maybe you could use/borrow a gps and verify your tach against it.......then if it isnt accurate try to fix it.

 

[alden135]

Re: how to tell if the speedomiter works

It does not take a lot of pressure to get the needle to move.

 

[Chinewalker]

Re: how to tell if the speedomiter works

It does on my old Keller speedo. Of course, it STARTS at 45mph!<br />On a standard speedo you should be able to at least budge the needle with breath pressure. I think my brothers and I busted a few blood vessels when we were kids trying to outdo each other blowing into one of those things...<br />- Scott

 

[KRS]

Re: how to tell if the speedomiter works

Use a can of compressed air, like you'd clean a computer with.<br /><br />Or a regular compressor.<br /><br />If using either of these, then be sure you don't blow full force, just direct air across it until you see movement. I can get mine up to 45 mph with a can of compressed air blowing into the hole.<br /><br />If it isn't budging, then the pitot may be clogged, or the tube taking the pressure to the gauge is cracked (leaking), or the gauge is bad (the last probable reason).