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Homemade Manometer

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by L0Ki, Jun 7, 2008.

  1. After adjusting the valves on my GPX250 I thought I might as well sync the carbies seemed as though your supposed to after doing the valves.

    Problem is I don’t have a carb tune or whatever else there is out there, so in my cheapness decided to build my own curtesy of the Ninja 250 Wiki.

    Pics.
    aV2BXNV0.

    aV2BXVor.

    Its just two drink bottles. Two 32mm sink plugs with the thing in the middle taken out. And 1/4" ID and 3/8" OD tubing. Oh and any sort of liquid i put coloured water in mine.

    Hardest part was forcing the plugs into the top of the bottle. Had to sand down the edges slightly. But its a nice snug fit.

    I haven’t used it as of yet because I had to get ready for something tonight but i plan on doing it tomorrow. I did blow and suck on one side of the tube and it worked perfectly. Oh yea and its only good for two cyclinder bikes offcourse.

    So that’s it, just thought I’d show it off ;)


     
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  2. Good on ya for having a go. As long as all the joints are airtight, a manometer (even a home made one) is the most accurate way of getting a comparison between two (or more) different pressures. It should work fine.

    Just remember that, with most carburettor tappings, more throttle gives you less vacuum. I failed to register this the first time I balanced carbies by vacuum (being used to using an air-flow meter) and made a hell of a mess of it before it was pointed out to me :oops: .
     
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  3. i thought a manometer was a device for testing your manliness. when i say the first pic it looked like one of those beer-hat type devices.

    looks cool, good on ya for having a crack. i hope it works
     
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  4. Or a bong shhh dont tell the cops ;)

    I hope it works too.
     
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  5. What happens if the water is injested into the engine? Maybe low viscosity oil or fuel would be better? :-k
     
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  6. It cant be injested into the engine. Its the way the tubes are routed that doesnt allow it plus the amount of water u put in.

    Put simply the tube that connects to the carb is right at the top of the bottle and the water would have to fill right up to the top. It cant do that because i put a certian amount of water in each bottle so that if one was to drain fully the others water level would still be a fair way from the top.

    But yea oil can be used.
     
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  7. Even if the engine did have a bit of a drink, the sort of flow rate that could be achieved through the weeny drilling in a vacuum tapping would be very unlikely to do any damage. There'd certainly be no chance of a hydraulic lock, which is the main way in which water can do catastrophic damage.

    That only happens when you hit that creek at 80 km/h and a big slug of water goes up the air intake :( :LOL: .
     
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  8. Update:

    Bottles are too weak to use accurately. They just crumple up so there must be alot of vacuum pressure as they were reasonably sturdy.

    I managed to get something done and it seems to have helped the return to idle etc atleast theres no noticable hang.

    Now just to do the final idle mixture tune probably tomorow as i ran out of time and am not watching the roosters :( get flogged.
     
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  9. Your device is fundemanetlly sound. However, just use one bottle.
    Route both lines into teh one bottle and fill the bottle to teh brin, and have a small amount of coloured liquid in teh hoses. Attach a simple scale between the hoses, connect hoses to scale. Then read the gauges off the level in the hoses.
    I would recommend a slightly more viscous fluid, like auto trans fluid to dampen the device a little, an also it will be red, so easier to view.
    Consider also fitting a couple of dampers to the lines just before the carbs to dampen pulses, the small, cheap plastic valves available in aquarium supply stores or pet stores will work.
    I had a go at making one of these, but just ended up buying a pair of vacuum gaiges. Much more useful.

    Regards, Andrew.
     
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  10. I'd love to see what you use to butter toast! :LOL: :LOL:

    For a twin, you don't need ANY joiners, valves, bottles, dampers, gauges, aquariums or anything more than a single piece of 5 metres of tube and a small amount of ATF.

    I'll take a picture of the extremely accurate unit I made for the R65.
     
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  11. I thought a manometer would measure things in inches, but perhaps I am thinking of something else... :-k
     
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  12. Ahh, BMW rider. That explains the ego.

    Regards, Andrew.
     
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  13. Yeah, I was expecting to see the Chopper Reed clip again :rofl:.
     
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  14. Yea i read about this one but it will suck in whatever you use in the tube if your not careful. The other way was fool proof or so i thought! :roll:
     
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  15. Where's your sense of humor? Was meant in jest...
     
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  16. Version 2.0

    Just thought I'd update the thread with a working manometre.

    Used it on my bike today, worked fine. It was just hard for me to get the adjustment right as it gets very touchy.

    Pictures. (You can kind of see what happened to version 1 too.)

    aVeXXY9.

    aVeYbW0.

    Basdically just some $2 glass bottle for wine i think.
    and once again sink plugs that i had laying around.
     
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  17. Here are the two I made, back to back on the same piece of special instrument grade refuse timber.

    For balancing 4 carbs or throttle bodies:

    [​IMG]

    For balancing 2 carbs on the R65:

    [​IMG]

    Each one has about 2m tubes which are more than enough to dampen the impulses and give you ample time to shut the motor down if things are so far out of balance that the engine looks like it wants a drink. Fluid is Dexron III ATF.

    About $5 for the 2 carb version, and about $10 for the 4. Works beaut!
     
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  18. Good work.That set up is probably more accurate than a bought vacuum gauge.
     
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  19. Made an example of the second one for mine, as long as you have the reference (non adjustable) carby hooked up, you're all set for a 4 carb tune.
     
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