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Sat Apr 16, 2011 7:37 am

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I wonder what John Welsford, the folks at SCA and MW Maritime Center and others think of a "motorwell" idea for SCAMP in motorcruiser mode. Would it be an extra bulkhead and longitudinals box right at the stern with a lower transom bottom cutaway for tilt up or a longer narrow isolated mostly open topped well box further forward? Would there still be room to sleep? It would be great to preserve the compactness of SCAMP and be able to leave the motor all set up inboard of the transom. Is it possible to somehow convert a 2hp honda or such to portable plastic red tank feed for greater fuel range and avoid underway toptank fueling?



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Sun Apr 17, 2011 3:54 pm

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I had a 2hp Honda, and will own one again when I build a Scamp. I don't believe it would be easy to convert one to a fuel pump system, others may have experience with that.

The local trailer sailing group gave me a pointer: Use the MSR camping fuel bottles. They hold about 22 oz. each. Run the motor until it falters just a little. Kill it. Slam one of those bottles in, it will only fill it about 3/4 full, but you don't have to worry about spilling everywhere. A yank of the cord and on you go. With a bit of practice takes no time at all.

I've thought one could make a motor mount which would slide vertically, rather than tipping to horizontal, that would work with Scamp's transom.
Bill P, Florida



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Thu Feb 02, 2012 6:12 pm

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I'll be using the 4HP Yamaha four-stroke that I already own and use on my Caledonia Yawl. As Mr. Welsford informed me, it's about twice as much motor as SCAMP needs to reach maximum hull speed but there are advantages. The biggest one is the remote fuel tank (I use a three gallon) that gives me incredible range without refueling. Also a four horse motor running at half throttle is much quieter than a 2HP running full out. John wrote that my four horse four stroke should yield almost twenty miles per gallon which should give me a range without refueling of about fifty miles or so with the three gallon tank during ten hours of time. Also the four horse running at half throttle should not have any problem or strain itself doing the ten hours straight. Whether my back can withstand 10 hours of motoring in a SCAMP is another question entirely but it's good to know the set up presents that capability.

My 4HP will be centrally located on the transom and I have commissioned John to draw me twin rudders (with linkage to each other) for the transom. John wants to hang the motor directly on the transom but I will be lobbying strongly for a small inset motor well. My boat will be only used by two of us guys fishing so I think I can afford the space the interior motor well will take. For more than two I will simply use my Caledonia Yawl. I haven't confessed this to John yet but the real reason I need the motor inside the transom is so I can display my SCAMP's name properly on the transom. My Caledonia Yawl's name is Xena so naturally my SCAMP will need to be named Gabrielle. Don't really want to see that motor obscuring the long name for the little sidekick of a boat. Us old guys have to keep ourselves entertained.



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Fri Feb 03, 2012 7:29 am

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kenjamin wrote:
I'll be using the 4HP Yamaha four-stroke

i use a 4HP suzuki on my M17 ... and to go along 4.8 knots the motor is is set at just over 1/2 throttle.

kenjamin wrote:
... a 2HP running full out.

really doubt a honda 2HP will need to do more than 1/2 throttle to be pushing hull speed. i used a honda 2HP on my M15 and at 1/2 throttle the boat was doing 4.5 knots.

i use a honda 2HP on Sage 17 ... she does 4.8 knots at 2/3rd throttle.

my experience is that the honda 2HP at 1/2 throttle is quieter than my suzuki 4 HP at 1/2 power.

on my M15 my practice was to run the honda 2HP just under 1/2 throttle and go about 4.3 knots. motor wasn't at all loud (for a 1 cylinder outboard) and i could go for one hour and 15 minutes between needing to fill the motor with gas.

IMO at 60+ pound 4HP motor on SCAMP's transom is HUGE and unnecessary overkill.

i believe that if any outboard manufacturer ever marketed a 2HP 4-cycle with an external tank there would be LOTS of happy pocket cruisers!

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Fri Feb 03, 2012 7:41 am

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billdprat wrote:
I don't believe it would be easy to convert one to a fuel pump system,

correct as the Honda 2HP has no fuel pump (gravity feed).

there are some 'external tank mods' discussed that use a primer bulb to transfer fuel from a bigger tank to the honda's internal and avoiding the need to hold a fuel canister over the transom and hot motor -

Captain Howie's Fuel Supply System -

http://www.wwpotterowners.com/Modification141.html


another mod ... don't know how it works as there is no follow-up discussion -

http://homepage.mac.com/storm_boy/iblog ... 8/index.ht


one more -

http://www.nwpotters.org/mods/elnino/gastankmod.html

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:: Dave Scobie
:: Sage Marine: building the Jerry Montgomery designed Sage 17
:: Check out the Sage 17 - http://www.sagemarine.us
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:: Owner of M17 #375 - SWEET PEA
:: visit SWEET PEA's www-site - http://www.m17-375.webs.com



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Fri Feb 03, 2012 8:43 am

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Quote:
IMO at 60+ pound 4HP motor on SCAMP's transom is HUGE and unnecessary overkill.


I second Scobie's comment. I can't imagine a 4HP motor anywhere on SCAMP. FWIW. —Josh

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Fri Feb 03, 2012 1:11 pm

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For those who would like to add a fuel pump to an engine that does not already have one there are several alternatives.

If you have 12v DC electricity available then a simple electric fuel pump can be installed.

If you don't have electricity then you can install a pulse pump (Google the words "MIKUNI SINGLE FUEL PUMP"). Pulse pumps use the high/low pressure pulses generated in the motors crankcase to actuate a small diaphram pump. These pumps are commonly used in ultralight aircraft, snowmobiles and other applications where gravity feed is not possible. They are inexpensive (~$21), small and very reliable. In some cases the crankcase ventilation tube can be used as the pulse port thus requiring no mod's to the engine. I have dealt with these type pumps and would be happy to discuss them further if there is any interest.

Tony
SCAMP 98



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Fri Feb 03, 2012 5:42 pm

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For the record the Yamaha 4HP fourstroke is 47 lbs. dry weight and it's always dry with the remote fuel tank. I believe the Honda 2HP air-cooled outboard is 27 lbs. dry but you have to add a couple of pounds for that whopping liter of fuel that it can hold.

47 lbs. - 29 lbs. = 18 lbs.

18 lbs. is a pretty small weight penalty for tremendous range without refueling, lots of reserve power and a motor that can move the boat well with very little strain all day and into the night if needed.

The smaller the boat, the bigger the fish look.



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Sat Feb 04, 2012 10:12 am

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kenjamin wrote:
For the record the Yamaha 4HP fourstroke is 47 lbs.

yamaha's www-site lists the 4HP, short shaft, as weighing 60lbs -

http://www.yamaha-motor.com/Outboard/pr ... specs.aspx

_________________
--
:: Dave Scobie
:: Sage Marine: building the Jerry Montgomery designed Sage 17
:: Check out the Sage 17 - http://www.sagemarine.us
::
:: Owner of M17 #375 - SWEET PEA
:: visit SWEET PEA's www-site - http://www.m17-375.webs.com



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Sat Feb 04, 2012 4:24 pm

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I bought mine back in 2006 and at that time evidently they had a special size for the 4 HP then. Looks like now they're making the 4HP out of the 6 HP because they are both 60 lbs.

Someday one of these outboard manufactures are going to produce a 3 HP four-stroke with a remote fuel tank and make a fortune.

Sorry to hear they stopped making my outboard!



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