Honda 50hp 2006 altitude issue.

stormmnv

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Nov 12, 2011
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I have a 2006 Honda 50hp. carbureted, I fish from 2k foot lakes to 8k ft. lakes on a weekly basis.
As you may guess, the engine runs fine at 2k but hardly at all at 8k... Other than re-jetting every other week, (not practical) is there an easy solution other than selling the engine and buying a EFI engine.

thanks
 

Sea Rider

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Sep 20, 2008
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Have 2 options, use 2K standard carb propped with 2-3 less pitch to pull wot revs higher or get a spare carb jetted for 8 K elevation. EFI's OB's don't make miracles at high elevations. My car which is EFI runs as a pig at 9 K and it's time advanced electronically controlled.

At high elevation a carb re jet and a less pitch prop is mandatory to perform way better, but not spot on as it's impossible for an OB to breath same as when at sea level when there's way less oxygen available. At elevation use the least fuel octane available..

Happy Boating
 
Last edited:

tommarvin

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Nov 22, 2015
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If your boating budget can buy EFI you will be happy.
We went for a Force 125HP carb to twin 115hp EFI at sea level, best decision we ever made, she's a beast.
 

Sea Rider

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An EFI outboard will perform better at high altitude than a carbed outboard, just don't expect it to be a real beast, EFI's too need to deal with oxygen and if there is way less than at sea level nothing can be done about that. EFI's cannot fabricate the same amount of oxygen found at sea level to work spot on. Going higher will get worse, anyway will still need a prop maximization...

Happy Boating
 

ahicks

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Sep 16, 2013
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Even though it will be down on power/rpms due to less oxygen at altitude, the EFI will at least let the engine run right by optimizing the fuel mixture fed to the engine. Where a set of carbs optimized for sea level will be running stinky pig rich, the EFI will correct for the altitude increase as part of it's design.

So yes, in your situation I would likely start saving my pennies for a later model injected Honda, maybe the new 60hp engine? The sale of a nice clean late model 50 hp Honda should help offset the price of the injected engine big time. There's still a bunch of us that prefer the carbs over the fuelies as they're much simpler to trouble shoot and work on (for us old timers). Point being, that carbed engine is not out dated by any shape of the imagination. There's still a big demand for them. Don't let some dealer try to steal it from you on trade saying it's an antique.
 

stormmnv

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Nov 12, 2011
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Thanks guys..... I have decided to order a new 70hp Yamaha and sell the 50 Honda....
 

pvanv

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If you like the Honda, buy a Tohatsu. The 75 hp Tohatsu uses a Honda powerhead.
 

Sea Rider

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So you're going for a new 70 HP, is it a 2 strokes carbed or EFI outboard ?

If being 2 or 4 strokes carbed models will have exact same issues, a larger CC engine will not solve altitude issues. Will need re jetting along a less pitch prop and on an EFI model a prop maximization. On all 3 models a prop maximization is the way to go once break in period has ended..

Happy Boating
 

stormmnv

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Nov 12, 2011
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just took delivery on a F70LHA 2016 Yamaha 13.5X15 prop. will see how it works... stormmn
 

ahicks

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Speaking for myself, I'd like to hear your thoughts after you get a chance to try it a few times?
 
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