New engine maintenance

Wood Zeppelin · Posted: Mon Jul 14, 2025 9:25 pm Post subject: New engine maintenance

I started getting the maintenance alarm awhile ago on my 2021 Honda BF100. The motor was put on about a year before I bought the boat, so I don't know the maintenance history. It now has 174 hours and I've owned it for a few years. I think the alarm started going off at 150hrs but I've ignored it until now.

I read that such an early maintenance interval on a new engine can be ignored until the next interval. What do people here think of this?

And I am ready to do maintenance, but what would it need after 174 hrs? Just oil engine oil change?

Any need to check gearcase oil / impeller?

Fuel filter / spark plugs?

Thanks!

thataway · Posted: Mon Jul 14, 2025 10:50 pm Post subject:

Once a year for engine oil/filter, or 100 hours, if running hard. You can space that out to 200 hours IF you are mostly at displacement speeds. Many cruises we take, we change oil in the middle of the cruise.

Oils and filters are the CHEAPEST part of any engine maintenance~.!!

The impeller depends on what type of conditions. If around sand or abrasive materials, each 100 hours. Again under lesser conditions, then 200 hours--Impeller, 300 hours, 3 years or if stream is less.

Go by manual maintenance intervals. Do it more often, than not often enough.

I was commenting on another forum, out of 70 years skippering boats, and tens of thousands of hours at sea, I have never had an engine failure. That does not mean I have not have to trouble shoot, and solve engine issues, or that I have not have overheat (due to cooling plug up). I have only had to have commercial assistance--and that time it was optional, for a few hundred yards to place our lives 62 foot ketch thru the last lock into the Baltic sea from the Kiel Canal, and get to the British Kiel Yacht Club due to a transmission outshaft failure--not the diesel engiene. I had to pull the transmission, and get the correct parts, outshaft and bearings. I could have done it myself, except a ferry boat crossed right in front of me, ruining the drift I had calculated, turning the boat hard to avoid this dump ferry boat!!

robhwa · Posted: Tue Jul 15, 2025 1:34 am Post subject:

After 4 years, you may be seriously due for maintenance. You can't be sure that continuing running won't damage your motor. New oil and filter are super easy and way overdue at 4 years, but at the very least look at the oil on the dipstick. If it doesn't feel really slick in your fingers, do not run your motor until you replace it. You should also probably at least check the quality of the lower unit lubricant, also an incredibly easy and important maintenance item. At this late date, I'd definitely take off the lower unit and replace the impeller...it is now 4 years old, probably at least partially hardened, and may damage the impeller housing if it is and you run the motor. I also have a 2021 Honda BF100, now with over 400 hours, and I've replaced the oil and filter 4 times and impeller 3 times...the first time for the impeller was 2 years and it was hardened and breaking apart. I do tend to take the CD22 into shallow water and sometimes probably take in muddy water. Seeing the bad condition of the impeller was amazing to me as my 2002 BF90 never looked like that when I changed them. After that I now replace it every 100 hours or 1 year. The motor can last several thousand hours if you take care of it (my previous 2002 Honda BF90 did). You can see how to do each of these maintenance items on Youtube if you don't already know how.

Wood Zeppelin · Posted: Tue Jul 15, 2025 3:01 am Post subject: Thanks!

Thank you both for your helpful responses.

Tomorrow I'll start in on Maintenance!

BTW, when they say things like "100hrs OR 1 year".. say you barely used it in that year. What's the concern? Like with engine oil, is it that the oil could be getting water in it due to condensation? Or some other age related issue?

thataway · Posted: Tue Jul 15, 2025 12:05 pm Post subject:

Yes, from the first time you start the engine with a new oil, there is contamination. It will eventually show up on bearing damage etc. There is more breakdown and contamination, the longer you run, and the higher speeds you run. I may go two years, but that would be rare. If I am shutting down an engine for the winter or I will not use it--I change the oil--cheap insurance--and with an extractor takes little time and minimal "mess".

Many of these engines can go to 10,000 hours, when used daily, not abused and regular full maintenace-as in Coast Guard, Harbor Patrol, and Law enforcement.