2006 Mercury 5hp- can it take 6hp carb?

[malbert73]

The 2006 Merc 5hp 4 stroke that came with my hard dinghy has a rusted out/gummed up carb. My inflatable that I use alternately can take a 6 hp motor. Can I replace the existing carb on my 5hp engine with a 6 hp carb and get a little more power?
The owner's manual is shared for 4-5-6 models and shows they share a block and pretty much the engines are the same. So I assume the holes, etc are same.

I called Mercury and they said the carb was "different" for each 4-5-6 hp model (of course!) and they don't endorse interchanging though acknowledge the different carb may fit. No surprise they don't comment on this probably as CYA, protect differential pricing, etc. I found online some posts from folks that you could swap the carbs as I intend on Tohatsu OBs.

Thanks for any input.

[a64pilot]

Some you can, some you can't.
As you have found out there is sometimes very little difference between outboards, and this is a good thing cause it makes parts easier to get.
Even big motors are this way, Mercury covers their entire Verado line with just two engines, 150 HP to I believe 400 HP

[mayday12]

yes you can - i did it to mine (longish story - motor died mid vacation, wanted 6hp, they only had 5hp) -got home, ordered a 6hp carb, it bolted right on no issues. according to the local merc guru its a fairly common swap, although usually 4 to 6. apparently though the only difference to all of them is the redline rpm - the 6 is several hundred more. i now have the 5 carb collecting dust on the shelf

[a64pilot]

But, but, but, if it didn't require a prop change, very likely you didn't gain anything, or very little. But if it fits and you need a new cab anyway, why not give it a try?

[mayday12]

well, there is never going to be a huge difference for 1hp, but for me (and most) every bit helps. But yes, all of that frame (4,5,6) come standard with the same prop. Technically the 6hp comes from the factory with the different carb, and the max RPM bumped up a couple hundred - unfortunately I was never able to find out how/if that can be changed on the 4,5 so not able to take full advantage of the extra fuel.

[a64pilot]

Little motor may not have a rev limiter, it may just simply turn a little more RPM

[malbert73]

Yes I think that's the difference. My guess is more air and fuel= more rpm. But I'll look at twist handle and see if there's a stop


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[mayday12]

yes there is a stop, but its just there to make sure you dont pull the cable out (i checked) does not limit throttle

[malbert73]

So the answer is "yes"
Motor runs great with 6hp carb. Who knows if it has more power as the old carb was gummed up when I bought dinghy that it came with. But price of new carb was same regardless of hp so seems this was a worthwhile way to go about it.



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