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Engine hours not accurate on one engine

Posted: March 24th, 2025, 10:34 am
by tgebler
My 2000 396 aft cabin had some engine work performed last year. Apparently, the ignition key for one engine was left on by the mechanic (engine not running) so the hours listed for that engine is approximately 100 hrs. more than the other engine. What if anything can I do to correct this problem?

I anticipate questions about the hours if I ever try to sell the boat.

Thanks.

Re: Engine hours not accurate on one engine

Posted: March 24th, 2025, 10:47 am
by bud37
Are you talking about what is shown on a dash gage ? What engines do you have ?

If they have electronic controllers then the running/idling/above a certain rpm hours etc, etc can all be seen by down loading the info from the ecu....at least it is available from mercruisers using Rinda software and some others.

Hopefully your marina mechanic can help with this. A good mech survey at purchase should have that info for the buyer to consider....IMO

Re: Engine hours not accurate on one engine

Posted: March 24th, 2025, 10:59 am
by Cooler
Typically, the the hours will not advance if the key is left on. There is usually a connection to the oil pump that should allow hour meter to run only when the engine is running. Is it possible a previous owner ran on one engine occasionally? Are you sure the meter is 100 hours off? My engines are off by 3 hours, but that is only because of the habit of starting one engine before the second one, and the accumulation of minutes over 30 years. I do not think there is a way to change the reading, that would be illegal anyway. I would just get a letter from the marine service stating they left the key on while servicing, which would account for the imbalance to a future buyer or surveyor. Good luck. 8-) er

Re: Engine hours not accurate on one engine

Posted: March 24th, 2025, 2:36 pm
by Viper
Ya knowing what engine make, model, and serial number you have would help. If it's not computer controlled and all you have are hour meters, the only way you can change what an hour meter displays is by applying 12 volts to it, but it will only advance forward, you can't reverse it. I never tried it but I think the only way to get back to a previous number is by running the gauge until it maxes out and resets back to zero then continue until the desired number of hours is reached, but that's impractical as you could be looking at a year or more. It would be faster to run the lower gauge until it reaches the same hours as the higher gauge, both engines though would look like they have 100 hours more on them then they actually do.

Re: Engine hours not accurate on one engine

Posted: March 24th, 2025, 9:18 pm
by Carverlvr2
Or disconnect the higher one and run the engines as normal until the actual engine hours catch back up to the what the gauge has and reconnect then? I also have one engine that’s about 30hrs under what the gauge shows. I suspect your same situation where a previous owner or mechanic left a key on.