With the 4 HP 4 stroke at 4.5mph, how many hours of running should I expect on the 3 gallon tank?
Has anyone actually tested this?
I could get 40 MPG with my SeaPearl running at 4.7 knots with a Honda 2 (2.5 hours running on .25 gallons).
But the SunCat is a heavier and beamier boat, so I wouldn't expect that kind of economy.
But maybe 20 MPG? If you can run for an hour on .5 gallons that would be 9 mpg. Will it go for an hour on .25 gallons? That would be 18 MPG.
Can you fit a 6 gallon tank in the space where tanks go? How about two 3 gallon tanks?
Thinking of long river and canal trips and have to know how far I can go between fill ups.
Thanks for your input!
Ron
Yep...a 6 gallon tank fits there. I have one in mine. Wally World used to have a fairly low one. A doubt the higher (fatter) tanks would fit. I've never actually figured it out but the 4hp Yamaha is extremely good on fuel. Throttle back into to the 4's and you will go a very long time! Mine is a 2004 and back then they won the "best fuel efficiency" award.
Ron,
The SunCat fuel compartment was designed by Hutchins (per their brochure) to take a 6 gallon tank - they don't specify what brand or model. I personally use a 3 gallon tank (from West Marine) and carry a spare one gallon container (made in 2008) Two will not fit side by side. The screw down cap is a bit tight and needs to have some vertical fingers sawed/filed down a little so that it can be cracked open (i.e. raised slightly) to breathe and move in and out of the storage space. The flatter 3 gal OMC tanks would not have that problem.
Fuel mileage for my Yamaha 4 hp - 4 stroke. is remarkable, probably as good as you quote for your Honda 2 but I never measured it . Only use it for going and coming from harbor at about 3 knots; guessing 10 hours = 1+ gallon (a whole season!) , so around 30 miles/gallon but a very rough guess....Type in "miles per gallon" to the search box to see an earlier interesting reference from Capt-Nemo on his research on this subject. The specific engine you have will make a big difference in the mileage...
hoddinr,
The YAMAHA 4 HP 4-stroke really sips fuel. Found that in a test a few years ago the YAMAHA 4 HP, on an unspecified small boat, at an unspecified speed, got 60 MILES PER GALLON!
I carry a 3 gallon tank which I normally fill only 1/3 to 1/2 full for local sailing along with a FULL 1 gallon spare tank. I add the 1 gallon of fuel when the 3 gallon tank gets low. If going on a long trip I would, of course, top them off.
Understand that some folks fit two 3 gallon tanks in the fuel compartment but having all that weight aft bothers me. If necessary, I would rather lash an extra fuel tank to the base of the mast.
The problem we face is fuel getting old in the tank because we don't use much of it. Old, stale, non-stabilized fuel has been the source of many problems that outboard owners experience. That's why I STABILIZE every ounce that goes in the tank. And, if not used for several weeks I empty the fuel tanks into my Chevy Blazer and go get a LITTLE fresh non-ethanol fuel for the outboard.
Once in a while I add a few ounces of Sea Foam to keep the carb and fuel lines clean.
If you find definitive information on fuel consumption for the YAMAHA 4 HP 4-stroke be sure to share it with us.
capt_nemo
My numbers are in Canadian units. I have a 12 Litre tank in the fuel compartment. And I can put 2 5 litre portable cans on their side down the side. It is a tight squeeze but they all fit nicely and hold things in place. I cut an access plate (4 or 5 inch) hole in the seat directly over the tank opening so that I can open and close the vent without removing the tank. There is still room in front of the fuel for a can of sea foam, oil and the bilge pump handle, some rags and other related gear. Note that it gets wet back there from the cockpit drain and when everyone sits at the back of the cockpit. We go for comfort over best sailing attitude! I have a Nissan 5 hp and figure I burn 0.75 litres per hour at 4.5 knots. I budget 1 hour per litre. I carry the 22 litres. I top them all up every 10 days or so when I get into a marina, I like to have full cans of fuel, may have to share with someone. We stay on the Sun Cat 5 weeks each summer and only stay in a marina once every 7-10 days, Rest of the time is at anchor.
Thanks Guys!
That helps a LOT. Yes, Don, I do have a Yamaha 4 stroke 4 hp, which I think is a 2006/7 model.
I do stabilize the gas, but use Stabile, and don't use Ethanol laced fuel. If I'm on a long trip though, I may not get to be so choosy, and that's why Stabil with Ethanol treatment will go along with me.
Depending on how far it is between fuel stops, I may need the 6 gallons, either in two 3's or in a 6.
I recently read a book about the Great Loop, where the author said there is 250 miles between fuel stops from the Ohio River to the Tennessee River. I'm sure he's talking about marinas with fuel offered, as there must be places where you could tie up and hike to a gas station with a folding hand truck and tank.
Jonathan Arthur, who Looped last year in a C-Dory 22 only fueled up at marinas twice on the whole trip, using the hand truck and jerry can method.
Thinking about a trip from Astor to Sanford and back on the St. John's River - a couple of long days each way with little sailing most likely. Perhaps I'll purchase a 1.25 gallon gas can for backup along the way. That's pretty wild area from what I've heard.
Thanks again!
Ron
Google for a WWP 15 w/ 2 2hp Hondas doing the great loop with mast removed - probably will tell something about consumption.
Next week I'll get a chance to test out the fuel milage with my Yamaha 4 and Nomad, the SunCat.
I'm going on a 4 day trip on the St. John's River, from Astor (near Hwy 40) to Sanford on Lake Monroe and return.
It's about 40 miles each way, so we'll stop at the Hontoon Island State Park where they have slips for visiting yachts, both going and returning.
I'll report back how we did on fuel consumption.
It will have to be an average of both ways, since the current will be against us going south and with us going north. Yes, the river flows north towards Jacksonville.
Ron
My guess 25 -30 MPG
25 MPG would be GREAT, Gus.
Ron
wow! gas milage on a sailboat-----what a concept
It has to be considered, MPG that is, particularly when cruising. Actually I always kept tract of gallons per hour. because miles per hour vary with wind strength, current, motor sailing or not all kinds of considerations. How many hours I had left in the tank then take into account the other conditions and I knew how for I could go.
Tom L.
Topped off the 3 gallon Yamaha tank, and found a 1 gallon extra tank in case I need it. Probably won't though.
Headed to Astor Florida tomorrow, for a Mon - Thursday 40 River Trip upstream, heading south, to Sanford.
Halfway there is Hontoon Island State Park where we'll meet up with By Miller and his Ranger 21 Tug.
Tuesday down to the big lake at Sanford, and a night in their marina. Dinner out and a shower.
Then Wednesday heading north again to Hontoon Island, and Thursday back to Astor.
Should give me a great idea how far we can go per gallon and gallons per hour.
Ron
Completed the 80 mile round trip up (to the south) the St. John's River from Astor to Sanford on Lake Monroe.
The current varied with the width of the river, but we averaged 4.7 MPH going and 6.4 MPH coming back.
I have estimated that we burned 1 gallon per 5 hours of running time upriver. At almost 5 MPH that would be 25 MPG.
Sounds like pretty good MPG consumption. Your thoughts?
capt_nemo
Quote from: hoddinr on March 07, 2015, 07:57:08 PM
Completed the 80 mile round trip up (to the south) the St. John's River from Astor to Sanford on Lake Monroe.
The current varied with the width of the river, but we averaged 4.7 MPH going and 6.4 MPH coming back.
I have estimated that we burned 1 gallon per 5 hours of running time upriver. At almost 5 MPH that would be 25 MPG.
Looks like between 25 - 30 to me (LOL)
Thanks for the report, Ron. I hope you will have time to favor us with a full trip report, including photos, in the Journeys, Anchorages and Destinations section of the forum.
Cattail Tom
I worked at a boat place years ago and the owner would tell people to expect to use .4 gal per hour on a 4 hp 4 stroke at hull speed. If someone bought a 9.9 he would say it will use just under 10. Put a decimal point ahead of the hp and you are good to go. Last week I spent 3 hours under power at around hull speed or slightly lower and used 1.5 gal of fuel. That is using my 4 hp 4 stroke at about 1/2 - 2/3 throttle.
Oh yeah, Don! Excellent fuel milage!
That's probably about 80 mile range on 3 gallons!
With an additional 1 gallon tag along tank it's over 100 miles for 4 gallons.
Very good economy!
Ron
Just some observations on this very interesting topic: If we use OntarioSuncat's figures (4 stroke 5HP Nissan) earlier in this thread and convert from his units to Miles per gallon he gets 23.2 mpg.. If we use Hoddinr's (4stroke, 4 HP Yamaha) exact number of 4.7 and convert to MPG we get 23.5. VERY SIMILAR !! Both were going approx. the same speed approx. 5mph (5.1 and 4.7 respectively). Those two numbers are better documented than the rest but it seems many think 25 mpg. My estimate earlier (4hp Yamaha) of 30 was based on less carefully measured numbers averaging 2 or 3 mph(not good data). Capt_Nemo literature reference of 60mpg (he cites it's unclear data) may be true but I'll bet it was for something like 1 mph? The old days boat yard estimate works out to 15 mpg but I wonder if that is for 2 cycle engines? or full throttle? So I guess I'd go with 23.4 as this thread's best number for (4-5 hp 4 stroke Tohatsu, Nissan, Yamaha etc) so far, but remembering its for 5 mph. Any thoughts?
Quote from: FireDrill on March 10, 2015, 09:38:17 AM
So I guess I'd go with 23.4 as this thread's best number for (4-5 hp 4 stroke Tohatsu, Nissan, Yamaha etc) so far, but remembering its for 5 mph. Any thoughts?
I got a little over 18 mpg with a 9.9HP 4 stroke on a Com-Pac 23 at 5 mph, 20-25 seems pretty reasonable for a smaller motor/boat at the same speed.
If I said I was going 4.7 knots, I mis-spoke. I was measuring MPH. I used to do everything in Nautical Miles, but now that I'm mostly inland and Intracoastal I'm using MPH.
The only thing that's not clear to me is how the river current affected the speed and fuel consumption.
Best would be to average the upstream and downstream mileage to get the overall mileage for the whole trip. Since I haven't topped off the tank since returning, I don't know for sure how much I used on the way back. My bet would be LESS. I tried to keep the same RPM, and throttle position on the handle both upstream and downstream. Upstream I was going 4.7 MPH - Same RPM downstream yielded 6.4 - 6.5 MPG. A lot less time to cover the same distance at the same engine RPM.
Ron
Quote from: hoddinr on March 10, 2015, 02:17:39 PM
If I said I was going 4.7 knots, I mis-spoke. I was measuring MPH. I used to do everything in Nautical Miles, but now that I'm mostly inland and Intracoastal I'm using MPH.
The only thing that's not clear to me is how the river current affected the speed and fuel consumption.
Best would be to average the upstream and downstream mileage to get the overall mileage for the whole trip. Since I haven't topped off the tank since returning, I don't know for sure how much I used on the way back. My bet would be LESS. I tried to keep the same RPM, and throttle position on the handle both upstream and downstream. Upstream I was going 4.7 MPH - Same RPM downstream yielded 6.4 - 6.5 MPG. A lot less time to cover the same distance at the same engine RPM.
Ron
Top Off, Top Off, Top Off!
PS I think you meant MPH, not MPG on your downstream trip (LOL)
Sharp eyes, Gus. Yes... MPH not MPG.
Quote from: hoddinr on March 11, 2015, 08:39:16 PM
Sharp eyes, Gus. Yes... MPH not MPG.
My Mother was a "Proof Reader" for the Buffalo Evening News back in the day, so I grew up with that and was "Properly" trained.
Hoddinr - good comment about the effect of the current!
I believe the difference between your two speeds divided by 2 is the effect of the current. i.e. 1.7/2 = .85 mph (+ or - depending on direction ). Since you kept RPMs the same that means we can apply results to MPG calculation at that rpm. So the speed upriver without current would have been 5.55 mph (getting near hull speed of 6mph in still water) going 27.75 miles on 1 gallon of gas at your fixed rpm. So its more like 28 MPG !. The actual current may have been greater than .85 mph, that is simply the calculated effect on your suncat's hull... (I am an optical engineer, not a mechanical engineer so this may be too simple of an explanation) Looking at some manufacturer's data on various outboards, there is generally a sweet spot on fuel mileage in the lower rpm ranges, and I think you said you were mid throttle - i.e. mid rpm range probably.
Any thoughts.? Other insights on the effect of current?
Atrometer - I grew up in Buffalo - back in the day - and loved reading the Buffalo Evening News - no wonder it was so good !
1/2 way through 4th grade in Kenmore, moved to Michigan - small world & my Dad was a U of M mechanical engineer.
OK.. so I topped off the 3 gallon tank today in preparation for this weekend's Cayo Costa Cruise with the WCTSS.
It took .95 gallons. So let's say 1 gallon. I used a 1 gallon spare tank on the trip, and had an attendant at a pump put in .8 gallons. So total used for the 80 mile St. John's River Trip was 2.8 gallons.
That figures out to be 28.57 miles per gallon. Even better than I thought!
So I can be pretty safe in saying I have a 75 mile cruising range with the 3 galloon tank, with room for safety. That is if the wind and waves are not right in my face. That changes everything, and would be a good reason to start sailing!
Ron
Good information Thanks.
Mike