Re-setting an hour meter

So I had an hour meter installed at the helm when I bought my boat. This spring, after getting the sonar units back on the boat when getting it ready for another season, I had turned the key to the accessory position to test the units, but failed to turn the key off when I was done. Ten days later, go back to fiddle with something, and notice I had left the key in accessory mode which resulted in an extra 240 hours on the hour meter.
Is there an easy way of re-setting the hour meter to remove the 240 hours? Maybe disconnect the wires from ignition and connect to a battery in reverse polarity for 10 days? Or will that fry the hour meter?

What do you use your hour meter for? Depending on your motor, the computer knows the true hours.

Either hook it up and run it forward to zero and then to your desired reading. Or purchase a new one and run it to your desired reading.

Doubt it will run backwards, but you can certainly try it and if it fries buy a new one.

I would recommend not reversing polarity.

z-man wrote:

So I had an hour meter installed at the helm when I bought my boat. This spring, after getting the sonar units back on the boat when getting it ready for another season, I had turned the key to the accessory position to test the units, but failed to turn the key off when I was done. Ten days later, go back to fiddle with something, and notice I had left the key in accessory mode which resulted in an extra 240 hours on the hour meter.
Is there an easy way of re-setting the hour meter to remove the 240 hours? Maybe disconnect the wires from ignition and connect to a battery in reverse polarity for 10 days? Or will that fry the hour meter?

Make/model/year of engine?Also what brand of hour meter?I know on Yamaha gauges,the hours cannot be reset within reason and only log hours if engine is running.The same for Honda,the factory gauge has an hour meter symbol that flashes when logging hours.Does not flash if key is on and no engine run.

Not sure if the ECM did log those hours,trip to dealer could confirm.

The hour meter is an aftermarket brand installed by dealer. Not sure of name. I do much of my own routine maintenance, so need to know the approx. hours, and had it installed so as not to have to run to dealer an hour each way, especially just to read the hours. Good idea on just disconnecting from ignition and hooking it up to a battery to run forward till I get to desired hour reading of 38 hours. Will only take about 40 days but this time of year, I have the time to let it run, and should be ready to go for the late January warm up and Lake Michigan harbor bite. Or, could go on as I have been, and make the adjustment calc for the oops hours.

Unhook it for the next 240 hours

Or, buy a new one of same brand/model and only run it 38 hours!

Seems like this will be a constant issue going forward, very easy to leave the key on for a variety of reasons.

Replace with an inductive unit instead? I think they’re about $20. Seem to work fine, only downside is they use a battery but the ones I’ve installed will hold the memory when the battery is changed. Just an idea.

Grouse

That would be an easy solution. Will check into those.