Routine Maintenance

[Tony B]

Routine Maintenance
I just bought a 1986 36’ Mainship Dual Cabin with twin 350 crusaders.
Probably 90% of the time I will be doing 6-7 Kts and sometimes 15 – 18 kts, but not all that often and I will be taking long trips.
Since I am new to mid size power boats, I will act? like I don’t know anything.
Sooooooooo……..What routine maintenance do you guys do, and at what frequency, whether it be in months, engine hours or whatever?
Thanks in advance
Tony B

 

[Marin]

We use engine hours to measure our routine engine service. I made up log sheets similar to what we use in the floatplane to track trip hours, total hours, hours since lube oil and filter change, hours since injection pump oil change, generator oil change and so on.

Items like impeller, belt, and coolant changes are tracked by date.

 

[Budds Outlet]

Glad to see you've acquired a power boat Tony, congratulation!

And while I know that you are an experianced boater I will throw out my 2 cents of advice.
Of all the maintenance items, unless you know for sure when the raw water impellors were changed out, I'd start by replacing them. I use a period of 3 yrs/100-150 hrs on my impellors and its seems to be right.

 

[Giggitoni]

I'll second that! No impellers, no go...or only for a short distance, anyway.

 

[Tony B]

How many hours do you go before oil changes, filter changes, etc.?

If I sound retarded it's because I'm used to my sailboats and diesel engines that I service everything once a year. never have much hours on them in a given year.

 

[Tony B]

Thanks for the congrats Bud.
Now if I could just sell my sailboat before hurricane season in the Gulf

 

[Budds Outlet]

In a normal year I will put on between 35 and 60 engine hours and operate over a five month period.

I change the oil and oil filter, fuel filters, Rotor, Cap and spark plugs once each season.

Also, I clean the spark arrestor once a year by dousing it with brake cleaner or carb cleaner.

I don't know anything about the Crusader exhaust but the risers on the Mercruisers rust out and need replacing.

BTW, that is a lot of accomodations for the size of the boat. Nice choice. Do you know what the headroom is in the salon and aft cabin? Do you know what your gph or mpg will be?

 

[Tony B]

...........I don't know anything about the Crusader exhaust but the risers on the Mercruisers rust out and need replacing.
All of the risers will be replaced when I get in from offshore. The flanges all show rust. A professional mechanic will look at it and do what is necessary. Tony B

... Do you know what the headroom is in the salon and aft cabin?
I have no idea. I'm 5-9 and dont have a problem. Tony B

Do you know what your gph or mpg will be?
Yes. I had met someone on a different forum and they have the same boat/same year. They did the great loop several years back and meticulously recorded everything. They had the FloScan units to measure fuel consumption. Tony B

Thanks for the above info.
Now for your last question: Their trip was 5,800 miles. They logged in at various speeds using only one engine at a time and also running the twins.
If you run on only one engine and leave the other in neutral, you will get about 2/mpg at 7 MPH. They sent me a chart of what they did. I am going to try to post it on here as a .jpg
The results are going to be contrary to what almost everyone on here has told me in the past. I never was convinced of what everyone said. It just did not make sense. Anyway, here is the chart he made.

Tony B

 

[Budds Outlet]

Thanks for the chart Tony. That provides some interesting information. Too bad I can't put my single 454 in neutral and still get 2 miles per gallon.