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Engine Hour Meter Answered

Hi, I'm trying to bodge up an engine hour meter for my motorbike (single cylinder) and I'm hoping to find a circuit diagram somewhere. I know you can buy these ready to go but apart from the fact that I have several motorbikes and they are about $NZ90 each, well it just isn't the point, is it? Why spend money when for the sake of a few hours cursing at dodgy connections and burning myself with asoldering iron I can play creator!! Any info would be appreciated, thanks. Nick



11 years ago

Thanks for the feedback people - to clarify: an engine hourmeter logs the running time of the engine for maintenance purposes. The type used commonly on dirt bikes gets a signal from the high tension lead (spark plug lead). They must have an on board battery to retain info while engine is off as most dirt bikes don't have a battery. The clever ones show hours while engine is not running and rpm while engine runs! Again, I could buy one but I'd like to build my own - save some money and make myself a better/more knowledgable person!!! And I can't help but feel they must be a relatively simple device.

. Oh . Most hour meters I've seen have a mechanical display so it doesn't need power to retain memory. I don't think the high tension wire is used for the hour meter, but is for the tach. . I'm with dickie, try to find a cheap one at a lawn and garden shop instead of a motorcycle shop.

Couldn't you just get a cheap pic and a quartz chip and wire it up (I'm not exactly sure how :p) and program it to keep the time (connect it directly to the batter if you have electric start) and then there would probably be some kind of input pins, so you could wire it to the ignition so that when you turn the bike on, it comes out of standby and starts the clock again. What exactly do you need a hour counter on a bike for anyways? If you need to time something, just get a watch.

You need a timer circuit that you can separate the counting function from the memory function. That way, you can keep battery power to the memory and run engine power to the counting function so that it counts up time only when getting power from the engine. The trick would be getting the right power source from the engine (I'm guessing magneto?). If you wanted to do it mechanically, almost all heavy equipment has an engine hour meter. You could try to get one of those from a junkyard or repair shop.

What exactly does an engine hour meter do? Record how long it has been turned on?

they sell them at sears for not much money there used to keep track of time on a lawn tractor

. The only thing I can think of is a cheap electrical clock; wire power to ignition. It will roll-over every twelve hours.