h a l f b a k e r y
Invented by someone French.
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Hate having to travel to the parts counter or special tools locker for a mini-tach when preforming a carbsync/idle-drop? I know I do. Employing the principals of mutual induction, a tachometer separate from the motorcycle's own tachometer is necessary to preform such tests. Commercially available
and relatively small and cheap, this proves to be an absolute necessity to the mechanic in the field. But what if you're lazy? What if you're yards away from your toolbox of goodies at the track and can't afford to 'wing it?
Enter the Mechanic's Dirty Cheating Tach-o-Watch! Encorporated into this lovely timepiece is just such a compact tachometer. Unwinding from around the outer-dial portion of the watch lies a single, lowly wire about 10-inches long that is to be wrapped around the secondary-side plug wire extending from your coil. After it's been wrapped securely around the plug wire, adjust the digital read-out on the watch face using the tuning-buttons to 2/4 stroke operation, and how many cylinders the model has that you're working on. Now with a quick glance at your watch, you can tell within 500 RPM what the engine speed of the motor is.
In addition, you're usually having to hold the tach in your hand as you preform these tasks, or having to otherwise make a mess of things and try and mount the tach to the until you're working on - possibly damaging chrome surfaces, or damaging the tachometer itself. Now you've got an extra hand to hold your carb adjusting/sync tool as you work. Careful not to get too close to any exhaust/manifold plumbing while using the tachometer function of the watch. Usually the coils are some place hot and cramped. In which case, longer sensing wires are available at a nominal cost.
MacGuyver meets Motorcycles. Just the way it should be.
Example of convetional watch Tachometer.
[Letsbuildafort, May 05 2006]
Similar tech - The Tiny Tach
Operation Instuctions [Letsbuildafort, May 05 2006]
Principal of Mutual Induction
How one wire can get you an RPM reading. [Letsbuildafort, May 05 2006]
More similar tech.
Mini Tach/hour meter. [Letsbuildafort, May 12 2006]
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||I knew this was yours from the title (+). Can you do carb sync with it also?
||Sure - In order to preform a carb sync, you need to get the factory spec base RPM, and set the carburetors accordingly. As you proceed with the setting, the RPM will increase and fall with the adjustments you make. All the while you need to constantly be on top the engine RPM to do it properly.
||So basically you have taken a bog standard tachometer and added some velcro to the back so you can wear it on your wrist. Brilliant! Bun for you!
||And it tells current time and date. I had in mind something that was supplimental to a wrist watch, not just a mini-tach with a wristband.
||But that latter isn't such a bad idea either.
||Will the Mechanic's Dirty Cheating Box Set be ready in time for Christmas?
||[Brau] I was invisioning a digital read-out. Oft times thats a lot more precise than a dial indicator-style tach.
||[hidden] I like to think that anything is possible with the right amount of will, determination, and vast amounts of expendible labor.