Bender

[Dragonfly DIY] Adding an hour meter to a small engine

An hour meter is a great way to manage maintenance on small engines for generators, lawn mowers and the like. And it is < $10 and < 5 minutes to install to boot.

I picked up this hour meter (branded discoGoods) from Amazon for $6.99 US. It's a standard unit that's sold under many brands. It has a permanently potted in battery, which is a little troublesome since that unit claims a "2 year battery life" - that's nowhere near long enough and I hope it actually runs longer than that (my primary generator is already 10 years old and is barely a baby).

Also this unit came with no instructions and no parts other than a length of wire. But it's easy to find installation instructions online.

In any case, installation couldn't be easier. It starts counting hours whenever it detects magnetic pulses sent to it via a wire that goes near the spark plug.

To install, just use a couple of zip ties (not included) to secure 5 to 7 wraps of the induction wire around the spark plug wire (do not strip any wire, no actual connection is made to the spark plug wire, it just wraps around it).





Then route the wire to where you want to put the hour meter, and run it through the slot on the back of the unit. Start the engine and confirm that the hourglass icon on the left blinks when the engine is running.

Secure the unit with some velcro, screws, sticky tape or whatever you choose.