Honda 5HP 4 Stroke RPM Changes With No Change To Throttle Position

[SomeGuyInaShirt]

I got a new Honda 5hp 4 stroke outboard in May of this year and after around 25 hours of use, the old carburetor packed it in; needle valve fouling, ostensibly.

I finally got a replacement which the seller claimed to be stock (it's not, the two carbs are definitely different) and now my top speed is about 2 knots lower and the WOT position can have downright sluggish speeds, can't even get on plane with an empty dinghy sometimes. Even stranger is sometimes the WOT RPM will change and increase enough to get on plane even though no change to throttle position occurred, what's going on? I checked WOT throttle position with the engine cover off and it is indeed as open as it can get so what gives?

[Pete7]

Were they genuine Honda carbs? E bay is full of cheap copies

Why wasn't the original carb repairable? carb fouling normally down to todays horrible petrol and definitely needs emptying out each time until the carbs are dry. Fish out the old carb and have a go at it, particularly if its only done 25 hours.

Pete

[SomeGuyInaShirt]

Originally Posted by Pete7

Were they genuine Honda carbs? E bay is full of cheap copies

Why wasn't the original carb repairable? carb fouling normally down to todays horrible petrol and definitely needs emptying out each time until the carbs are dry. Fish out the old carb and have a go at it, particularly if its only done 25 hours.

Pete

It appears as though they've made the float/needle assembly non removable on the new carbs. Engineered obsolescence? I'm sure I could fix it given the right tools and time but I haven't had either since the original carb calfed. Even the official warranty repair provider just ordered a new carb instead of the failed parts. Absurd since I only used ethanol gas once 12 liters maximum! My product review video on YouTube might just be me shot-putting the motor into the drink.

[catsketcher]

That is terrible. Cleaning out a carb is essential on any outboard. The small ones have no or basic fuel filters so get dirty easily. Are you sure you can't get the needle valve out? How do they keep it in when you pull the thing apart?

[SomeGuyInaShirt]

Originally Posted by catsketcher

That is terrible. Cleaning out a carb is essential on any outboard. The small ones have no or basic fuel filters so get dirty easily. Are you sure you can't get the needle valve out? How do they keep it in when you pull the thing apart?

The float and needle are connected via a flimsy wire clip and all must be removed to clean the needle and seat but the float is held in via what used to be a pin with threads on the ends but now it looks like a pin with the ends squished flat to prevent removal. I tried turning it but it just bends the whole flimsy assembly. I won't attempt it again without being shown specifically if and how it can be done. Been wrenching on cars and trucks for years and never saw anything like this. Oh and I even have a proper fuel filter that is new. All the jets were clear when I pulled them out too...weirdest thing.

[Mickeyrouse]

Re-build kits for carbs used on Honda are generally available. Cheaper than new.

[SomeGuyInaShirt]

Originally Posted by Mickeyrouse

Re-build kits for carbs used on Honda are generally available. Cheaper than new.

Yeah but how do I get the float pin out and then back in?

[Mickeyrouse]

I’ve never changed that pin. Are you sure you need to?

[Mickeyrouse]

BTW, untold awesome amounts of money are no doubt being spent to make carburetors cheaper, unrepairable, and disposable. Reminder when the idea of a plastic carburetor would have been seen as folly past incompetence? I have had decent luck getting after-market carbs on ebay- in some cases a complete carb cheaper than a rebuild kit.

[SomeGuyInaShirt]

Originally Posted by Mickeyrouse

BTW, untold awesome amounts of money are no doubt being spent to make carburetors cheaper, unrepairable, and disposable. Reminder when the idea of a plastic carburetor would have been seen as folly past incompetence? I have had decent luck getting after-market carbs on ebay- in some cases a complete carb cheaper than a rebuild kit.

The pin holds the needle in, yes. I think if I get a rebuild kit for an older model Honda and cut the pin out and tap the holes and replace the pin with threaded rod it might make the carb field repairable.

Yes engineered failure is aggravating. I absolutely lost all respect for Honda now. Definitely going to get a 2 stroke Yamaha next time.

[GordMay]

Honda BF5/BF5A Service Manual
➥ https://static1.squarespace.com/stat...ice+Manual.pdf

Honda BF5A Owner’s Manual
➥ https://cdn.powerequipment.honda.com...s/31ZV1636.pdf