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View Full Version : Repower 26ft Longboat with 1x200hp Honda



Leglicker
22-10-2008, 09:49 PM
Have owned for about 10 years running twin 70 Evinrudes 1988 two stroke ,goes good ,cruise 18knts at 4200 rpm in good conditions pushing about 3000+kg. ( w.o.t 25knts). Looking for more torque to punch in rough conditions + better economy and range.

Think 1x200hp Honda will be the right repower because of economy between 2000 to 4000rpm and flat torque band.

Boat is glass with reverse chine to flat keel and known as Hobson Solocraft (NW coast Tasmanian fishing boat)

Question: Given the hull efficiency under twin 70's what horsepower would be currently developing at 4200rpm and if repowered by 200hp Honda only dragging one gearbox what HP or rpm would I need to run at to achieve 18knt cruise and how much higher cruise could I expect while staying under 4000rpm?

This is my first thread, just joined last night. User name was meant to be Legliker, if no offence will leave as is. Its a long story but many years ago I did say I liked legs rather than outboards. I don't anymore! :o

Any thoughts on my repower conundrum will be most appreciated.

Kendall249
22-10-2008, 10:40 PM
IMO you would get 18kts at about 3-3500rpm at 4200 have to be mid 20's (depending on proping). I'm running a 24ft longboat with a 150 2s, get about 24knts at 4000 and 35knts at 5500, so thats what I basing my opinion on.

Cheers kendall

Spaniard_King
23-10-2008, 05:43 AM
I run a 225 on an Edencraft (very Heavy Hull) best economy is 3500-4500 rpm with the very best economy at 4100. I run a 16 solas for 22 knots at 4100 for 38 and a bit at 6000rpm. make sure you prop it to acheive 6000 for best economy;)

Leglicker
23-10-2008, 08:19 AM
Thanks Garry, The right prop is obviously a big issue. You have a deep vee and a Honda 225? How heavy and length? I would not run at higher rev range so thought 225 Vtec not neccessary.
Do you say economy (that is 20% less fuel )stretches to 4100 revs on this motor as Honda says only to 4000rpm then fuel useage starts to mirror other brands. About how many lph at 4100? Any wraps for Honda?
Thanking you.
Darryl.

Spaniard_King
23-10-2008, 08:28 AM
Darryl,

My Boat is 6.7 transom to boat nose. Average gear the boat weighs 2T without crew and there gear. In the water I would say close to 3T with 5 of us.

Depending on conditions I use 30-33L/hr at 22-24 knots.

Your asking the wrong guy for an opinion (I am a Honda Service Dealer) The Honda's are a technical engine and what will make the difference is the Dealer that fits the engine and maintains it. If fitted to spec and genuine honda parts/lubricants are used they are a fantastic engine.