350 Mariner - some questions/comments

[TonyC]

Source of the post Curious if anybody uses they're Mariner off shore? Really curious how this boat would do in open waters and against larger waves?

While we've never been "off shore", this past weekend in Lake Michigan we did travel in confused seas with 4+ waves. It was a slow go, continuously working on course corrections (AKA driving the boat) and we did get bumped around yet never felt like we were in any danger. Exciting but not sure if I'd want to do it for any extended time. We were following a trawler which did run in a straight line but did have significantly more roll due to the full displacement hull design.

Would I take it out in heavier seas? Nope. A man has to know his limits.

[Wkuhilltopperfan]

Yeah. I've hit some rollers that crashed over my bow but never felt threatened at all. The boat does very well in rough waters, but I doubt it would like getting beat up over and over

[feeez]

I have had a few bread encounters with some rough weather on Georgian Bay. I would not want to be doing that for hours on end in this boat. I found it to be hard work especially in following seas

[feeez]

Source of the post Fraser; because we had lots of time, we also tried the trawler speeds on a trip last August, and could not believe how little fuel we used. Compared to our on-plane cruising speeds, it was a tremendous difference.

http://www.boat-fuel-economy.com/mercury-mercruiser-3.0-181-fuel-consumption-us-gallons

I believe this is link shows a fairly accurate estimate.


Visiting Henry's, San Souci Island, Georgian Bay, 2015

Steve, Thanks for the calculator. I used it do some estimating on our boat. We are running the 350 MAG MPI. Attached is my results. Our boat comes on plane nicely at 3000 and I put a fair amount of tab to come up to that speed.
For all you younger members..... this is what retired computer nerds do when they retire and go boating

[TonyC]

Hi feez,

How many hours are on your motors?

We are half way through a trip from st. Joseph to Beaver Island. At a tad above 3200rpm @ 16.3 kt we are averaging .79 mpg. Just enough tab to level side to side. However, basing on GPS DTG we do not have autopilot so distance used in the calculation would be higher and consequently mpg increases.

We have found that out port engine burns up to 20% more fuel based on amount of fuel added at fill up. RPM same while in sync. 500 hours on both engines. Can't explain at this time. Any ideas or similar situations (from anyone)?

Thanks!

[feeez]

Source of the post Hi feez,

How many hours are on your motors?

We are half way through a trip from st. Joseph to Beaver Island. At a tad above 3200rpm @ 16.3 kt we are averaging .79 mpg. Just enough tab to level side to side. However, basing on GPS DTG we do not have autopilot so distance used in the calculation would be higher and consequently mpg increases.

We have found that out port engine burns up to 20% more fuel based on amount of fuel added at fill up. RPM same while in sync. 500 hours on both engines. Can't explain at this time. Any ideas or similar situations (from anyone)?

Thanks!

We have about 590 hours on the engines. The speed you get at 3200 sounds very close to what I see. I am putting what I feel is more tab that just to level, but that is just a comparison to our last boat which was a 28 foot express cruiser.

The discrepancy from port to starboard...... On our 2001 the Genny draws from that tank. Could that be it?

Fraser

[TonyC]

Thanks for the reply, Fraser. A good idea on the fuel use. However, we do not have a genset. The mystery continues.

[bud37]

I doubt that you will get two engines that use the same fuel......we had fuel flow indication (garmin) on the last boat , it was quite interesting to watch the changes, wind and sea changes would change the engine loading from one side to the other, tab changes etc. Now it could something like the props are tuned off a bit. Have you checked the tank fills over many fills??, some marinas are a little inconsistent.

You have MPI , I guess from the year... plug or wire getting tired on one side??I once had a sync gauge that was inaccurate as well....lots of stuff heh...maybe this is not helpful at all lol.....

[amanphoto]

Source of the post I doubt that you will get two engines that use the same fuel....

Is there a way to pump fuel from one tank to the other? Is there a way to even out the two fuel tank volume?

[Viper]

Source of the postIs there a way to pump fuel from one tank to the other? Is there a way to even out the two fuel tank volume?

There are fuel transfer pumps on the market that you could install to transfer fuel from one tank to the other. I've seen some Carvers with these so it may be a factory option. You can also even out tank levels by using the tank selector valves to draw only from the highest tank until the levels are the same and then switch back to isolate. I do this periodically as I use the generator a lot so eventually my port tank has less fuel than the other.