text: almost finished my marissa eco18 need answers - B & B Yachts Forum - messing-about Forums
  almost finished my marissa eco18 need answers
  By driver758, June 27, 2017 in B & B Yachts Forum
  marissa eco18 help
  OK down to the brass tax on this one.. wasn't easy as I live a million miles from supplies. That and I work 24 7... the wife nick named it the wreck cause it occupied the garage in various states for 4 yrs. Here is my questions.. do I need that large 18 gallon in floor tank with a Honda 40 or has everyone stuck with a portable. And if not what is the tank standard Moeller tank? 2. What is a decent size axle to put under her... got plans for a trailer but it really kinda pops it into a void when it comes to axles. Are you having trouble launching off a flat trailer with a wooden cradle or should I place the boat on a drop down?
  I'll bait... this is where I was 180 hrs ago... haven't locked the console down yet because I want to find out if I need a large tank.... I will be strapped to the floor of her fishing my fool head off every chance I get
  I don't know how far you plan on running with this boat. But I can tell you that I have run a 40 Suzuki with a 6 gallon fuel tank for hundreds of hours without a problem. Of course I do a lot of fishing in the course of the day, which does reduce the total fuel burn for a day. So an 18 gallon tank in my opinion is a lot. As far as a trailer, unless your boat is overloaded with weight in your materials, a 3.500 rated trailer should be fine. They normally come with the 13 inch tires. You can step up to the aluminum trailers that will have the 14 inch tires and will be rated a bit more, depending on the brand.
  Yup that's what I'm doing also... fishing... my first run will be in alberta, but my bucket list is Pacific salmon... I kind of figured that 18 gal was over kill but, what do I know?
  smccormick 28
  Looks like that engine would be getting 6 to 8 MPG in the midrange cruise rpms, so you can do some guestimating from there. Here are some performance bulletins. None for the exact boat but it gives you an idea.
  click on performance test on this page.
  https://marine.honda.com/outboards/motor-detail/BF40-50
  No 40hp tests but a hand full of 50s to give you some close data.
  https://marine.honda.com/outboards/performance
  You can always throw in a second tank for the longer days.
  I see that the boats they have are close. My weight with the motor and gear is at 1264 pds not including fuel or passengers. So I should be around 1800 pds give or take. I'm also an avid troller...mixed with fly fishing. I chase Lakers which usually hit at 60 ish feet. So I may be looking at that 18 gallon yet. I will leave the console as a screw down until I've gotten more data...usually I run 250 Hp and up. So I have no experience with the smaller engines. Hope I'm pleasantly surprised. Now I just need an axle length and I'm golden. Ps. 250 is too big for a lake round here . I miss the ocean.
  If you buy three 6 gallon portable fuel tanks you have paid for a 18 gallon tank. I like to have 25% reserve fuel on a trip in case the weather turns foul on me and my fuel economy goes to hell and I need the reserve to get home. The fuel down in the bilge is out of the way, cannot move and gives the boat the maximum stability.
  Portable tanks can be in the way and may be moved to the stern to be more out of the way and not put the boat in the ideal trim for optimum efficiency. You do not have fill the tank up if you are going on a short trip.
  If you are running at about 4000 rpm you will burn about 2 gallons an hour which is only 9 hours run without counting your reserve. Run faster and you will burn a lot more.
  I see that you are up in the cold country. This is yet another reason for being mindful about having a tank that's a lot more than you may need on a bad day. Do you have any non-ethanol gas up your way? If not make sure that you are mindful about draining your tank before you put the boat up for the winter, IMO. We use the gas in our vehicles when buying the ethanol stuff, even though we have the good stuff available. If not stale ethanol gas turns to jelly in a tank that's stored for a long while. After using the 60 hp Honda, they do recommend burning non-ethanol gas. If you have at least the premium octane gas, buy that anyway.
  Yeah oyster I'm a canuk... added some challenges when working in the -40 zone... good point on the ethanol... our low grade has a ten percent mix but can get around that with the high test which is 0% ethanol. Also a good point designer that the 3 gas tanks would be the same cost as an 18 . This is great input, that's why I'm here. Thanks and as smccormick....pointed out I should run at a good rate of miles per gallon.
  I had a built in 18 gallon tank on my OB-20 and was glad of it. I had a 25 hp 4-stroke Tohatsu on the boat. ALWAYS use ethanol free gas AND stabilizer. And run the gas out of the motor if it will be sitting awhile. I always run it out before
  e trailering the boat home.
  Still curious about the exact model number graham recommended for a gas tank. Had all that paperwork untill my basement backed up 3 yrs bk. Only manged to save the blueprints. Was a lot of head scratching to figure out which pieces were to be cut off of what sheet of plywood. But I made it. I think the way I would have approached the blueprint side would have been to place all the pieces that needed to be cut from one sheet of plywood on a plywood size sheet with heat transferable ink. That way once it's transfered the blueprint is history and can't be copied. Then a step by step guide following the same guide lines they use for building mini car models. Would take out the guess work.
  Do have more photos? Like to see more, much more.
  Keep an eye out.... Monday I'll drop start to finish photos if you would like. Need to document up here in Canada in order to prove homebuilt for registration purposes. . I'm just wrapping up the floor... sigh ran out of two part primer so I'm off on a 6 hour round trip to gather some more
  Sounds good, look forward to seeing your photos. Wow that's a long trip for Materials. Can you have them shipped?
  Lmao...yeah I could ship it but I would like to finish it before winter .
  Finally finished the boat here is her final pictures.... had a welder do up a Glen -l 1800 series trailer... simple design but a long wait.