Re: Boat speed
Hi Steelspike,
You are required to have 2 motors is that written "2 identical motors"?
I am not too sure, it is fundamentally a safety issue, I suppose one could have a kicker motor, no-one here does it though, the tendency is two identical motors. Curious!
A twin setup is surely slick setup but not the most efficient to operate.
So I am finding out and have to agree. The issue is that the boat is real cheap $ 5000. The hull is perfect and needs no work. All I have to do is to remove a poorly made storage area on the deck and to have it redecked and filled with floatation foam (also a must here). It has two 40hp self lube Mariners on it which have done less than 100 hours each. Thought I would keep the rig the same, if after piloting the boat for some time experience leads me to trade the pair in for something else I will. Somehow I doubt it as I use the boat seldom and fish maybe 6 times a year.
I find it interesting that yours cruises at 28 at 4,000 rpm but only 30 at probably 5,000 plus.The 2 I checked were 26 @ 4,000 & 37 @ 5,220,and
29 @ 4,000 and 38 @ 5,400.I suppose that has to do with the twin setup.
or hull design.
I have yet to pilot the boat and am taking information from the current owner, I think some things he does not know and he then guesses the answer. I think that you are probably more correct than what he is.
Was the 4,000 figure determined to be best GPH/MPG or just an arbertrary
figure?2 of the boats I checked the best figure on one was 4,000 the other was 3,500.speeds were within 2 mph.
It's just the round number of rev's he runs at. I would do tests to see which is most efficient, for 2mph it is neither here not there.
I use the BRP new motor site for my figures I assume it is at sea level.
Have you got a web site for me?
You probably know the rule of thumb for GPH is approximately 10% of the hp developed.
I did not know but that is useful. Is the hp quoted at the crank or at the prop? If at the crank what are typical losses through the gearbox?
If your boat is set up for 5,000 ft elevation I would think you will have to rejet for sea level.
If one goes down to a lower altitude for just a couple of days is it advisable to rejet? Is there information on motor vs. altitude vs. jet size?
Hi Texasmark,
I think you hit it on the head, us testosterone charged individuals want everything at max. It's like golf, you always want to be the longest down the fairway.
I have been seriously considering the speed issue and the truth be told I just want to get to a fishing hole in comfort, along with a couple of buddies and at a reasonable pace. I don't want to break down 15 miles from port, I want a good time.
From a fishing perspective the most important thing for me is to have as much deck space as possible, I am 260 lbs and 6'2", so are my mates. I would rather have an underpowered larger boat.
Hi Tashasdaddy,
I understand that as the air density changes with altitude so too must the mixture change.
What then about the about the increased compression and corresponding lift power output. Am I incorrect in believing that this could result still result in overrevving due to the increased power and that another prop may be option, even though the jetting is altered.
Thanks guys appreciate the input.
Andrew
PS: Has the site been down lately?
