Removing the float from a carb

[blackrose]

Does anyone know how I take this float off the carb. Does that pin come out somehow? I tried unscrewing and pulling it with rat nosed pliers but it's not moving. It's from my petrol outboard. 

 

When I took the float bowl off it was full of loose crap that looked like limescale so I just want to pull the jet (or whatever it's called) out that sits above the float in case some of it's got in there. 

 

Edited September 7, 2025 by blackrose

[Kingdom Isambard Brunel]

The pin taps out with a drift. Its part way already.

[Ken X]

Looking at the splined end of the pivot pin I suspect gentle tapping with a pin punch will release it and enable it to be slid out. Other opinions may vary.

 

Beaten to it by IKB.

🙂e

Edited September 7, 2025 by Ken X

[blackrose]

11 minutes ago, Kingdom Isambard Brunel said:

The pin taps out with a drift. Its part way already.

 

No it's not part way out. That's the head of the pin, the diameter of the pin shaft itself is much smaller. It would have to be a tiny drift, but I'll give it a try.

Edited September 7, 2025 by blackrose

[Alan de Enfield]

 

 

 

On Yamaha OBs that pin is tapered it only comes out one-way,- grip the end with a pair of pliers and wiggle it out.

(Just cleaned my Carb yesterday - due to blocked jets from being left with fuel in the carb).

Read the manual for that particular OB

[Tony Brooks]

If it won't pull and wriggle out, you could try cutting down a suitable diameter flat head nail and put the shank it hole or against the pin from the top of the photo. Then put a pair of pliers between the nail head and the pivot bracket that is part of the float chamber. Gently squeeze the pliers, but be wary of snapping the pivot bracket.

[blackrose]

52 minutes ago, Alan de Enfield said:

 

 

 

On Yamaha OBs that pin is tapered it only comes out one-way,- grip the end with a pair of pliers and wiggle it out.

(Just cleaned my Carb yesterday - due to blocked jets from being left with fuel in the carb).

Read the manual for that particular OB

 

This is a Suzuki. As I said I already tried gripping the head with pliers but it's not coming out. I only have the owner's manual not workshop manual and it doesn't cover taking the carb apart.

41 minutes ago, Tony Brooks said:

If it won't pull and wriggle out, you could try cutting down a suitable diameter flat head nail and put the shank it hole or against the pin from the top of the photo. Then put a pair of pliers between the nail head and the pivot bracket that is part of the float chamber. Gently squeeze the pliers, but be wary of snapping the pivot bracket.

 

Ok thanks

[Tacet]

Take care.  The alloy towers can break off driving the pin out

[Alan de Enfield]

38 minutes ago, blackrose said:

 

This is a Suzuki. As I said I already tried gripping the head with pliers but it's not coming out. I only have the owner's manual not workshop manual and it doesn't cover taking the carb apart.

 

Ok thanks

 

I bet you could find the workshop manual on line as a free download Pdf. (That where I found my Yamaha one)

[blackrose]

29 minutes ago, Tacet said:

Take care.  The alloy towers can break off driving the pin out

 

Is it possible to blow out the float jet channel with an airline without taking the float off or the jet out?

[Ronaldo47]

If it is a steel pin  in alloy, heating might loosen it due to differential thermal expansion. I once had to fit a new alloy piston to my Hillman Imp's engine (the old one had developed a crack across the crown), and the only way to remove the gudgeon pin was to put the piston and crank in an oil bath heated to around 120°C. At room temperature the pin was an interference fit and absolutely unmovable, but at 120°C it just fell out under gravity when removed from  the oil bath.

[blackrose]

42 minutes ago, Alan de Enfield said:

 

I bet you could find the workshop manual on line as a free download Pdf. (That where I found my Yamaha one)

 

I've just had a look but the websites all want you to sign up for free trials and add your card details..I don't suppose you're a YBW forum member as they've got it for free for members.

 

https://forums.ybw.com/threads/suzuki-df5-outboard-workshop-manual.576712/

21 minutes ago, Ronaldo47 said:

If it is a steel pin  in alloy, heating might loosen it due to differential thermal expansion. I once had to fit a new alloy piston to my Hillman Imp's engine (the old one had developed a crack across the crown), and the only way to remove the gudgeon pin was to put the piston and crank in an oil bath heated to around 120°C. At room temperature the pin was an interference fit and absolutely unmovable, but at 120°C it just fell out under gravity when removed from  the oil bath.

 

I sent think I'll be trying that. I'm bound to melt the plastic float.

[Alan de Enfield]

4 minutes ago, blackrose said:

I've just had a look but the websites all want you to sign up for free trials and add your card details..I don't suppose you're a YBW forum member as they've got it for free for members.

 

What model is it - I'll try and find a manual

 

NB : I was told by an OB sales company never to buy a Suzuki - they are far to complicated and (like modern cars) with complex 'electronics' - no simple fix's available.

 

My No2 son has a Suzuki 8hp which just would not run - he eventually found a company in Scotland, sent it off for service / repair, on its return it started and ran nicely, but never started again - has sat in my shed for 6 or 7 years.

 

I used to buy/sell and play about with OBs, the main brands are quite simple, which was why, when I saw a modern Yamaha 4Hp 4-stroke for sale - cannot be started - no fuel getting into carb, thought I can fix that, a couple of hours later away it went - now sits on the back of my little RIB tender.

 

 

 

 

Honda are the best (most reliable) brand, closely followed by Yamaha.

 

the instructions for the Yamaha float removal

 

 

Edited September 7, 2025 by Alan de Enfield

[Alan de Enfield]

 

 

 

I have found the service manual (320 pages) for the Suzuki 9.9 (there are plenty of others)  if thats any help

 

 

Suzuki 9.9hp Carb

 

 

[blackrose]

Thanks. Mine's the DF5. It doesn't seem that complicated. The carb looks fairly simple apart from how to remove that pin. I found the manual for the DF2.5 and the carb assembly diagram, but like the one you've shown above it doesn't explain how to get that pin out. I'm not sure the manual will be of much help.

Edited September 8, 2025 by blackrose

[Tony Brooks]

5 hours ago, blackrose said:

Thanks. Mine's the DF5. It doesn't seem that complicated. The carb looks fairly simple apart from how to remove that pin. I found the manual for the DF2.5 and the carb assembly diagram, but like the one you've shown above it doesn't explain how to get that pin out. I'm not sure the manual will be of much help.

 

On all those I have dealt with, on vehicles, small engines, and OBs, as has been said, the pin comes out. Often it is fairly loose because it is located by lugs/a recess in the part that the housing screws onto, but others need a small punch, or a pull and wiggle. If you can secure the assembly in a vice, you should be able to adapt a nail as a punch, but only use a light hammer (toffee hammer) for the reason others have explained.

Edited September 8, 2025 by Tony Brooks

[nicknorman]

5 hours ago, blackrose said:

Thanks. Mine's the DF5. It doesn't seem that complicated. The carb looks fairly simple apart from how to remove that pin. I found the manual for the DF2.5 and the carb assembly diagram, but like the one you've shown above it doesn't explain how to get that pin out. I'm not sure the manual will be of much help.

As Tony said, it just slides out. You can see that it has been knurled a bit by some crimping tool at the protruding end, this is so that the raised bits of the pin dig into the soft aluminium hole a bit, to stop it falling out. So I would suggest wriggle and pull rather than twisting. You might be able to push a bit from the other side by putting a smaller pin (ground nail etc) into a vice and inserting into the other end of the pin hole, pushing the carb into it a bit whilst wriggling and pulling on the protruding end. It shouldn’t be too difficult although I suppose aluminium corrosion arising from moisture in the fuel might make it hard if the pin hasn’t been out for many years.

[blackrose]

It definitely won't wiggle out. I haven't tried putting the carb in a vice yet and trying to tap it out with a punch.

 

On the other hand, some youtube videos I've just watched show a carb clean without actually taking the float off so perhaps I don't need to?

 

 

[Kingdom Isambard Brunel]

Possibly not.

We have to accept these days that many things are made not to be repaired, dismantled or serviced.

Be careful with using solvents on that plastic float.

[blackrose]

Thanks. If I'm taking main jets out do I just need to make a note of the number of turns of the screwdriver so that is reset correctly when I re-assemble?

[Tony Brooks]

10 minutes ago, blackrose said:

Thanks. If I'm taking main jets out do I just need to make a note of the number of turns of the screwdriver so that is reset correctly when I re-assemble?

 

That jet/emulsion tube is typically screwed down hard so it does not come undone. The mixture is fixed for higher speed running by the main jet and any adjustment that needs putting back in the same place is the idle adjustment screw, not a jet.

 

I did wonder if taking the thing in the centre out would be sufficient yesterday, but without a carb diagram I could not be sure, so deleted the part completed post.

Edited September 8, 2025 by Tony Brooks

[Alan de Enfield]

 

 

Yes - the only reason to remove the float is to give access to the 'pin' that cuts off the flow when the bowl is full - this (ideally) should be viewed as it can become scored or mucky meaning it does not shit shut off correctly.

 

You can remove the main jet and pilot jet without removing the float.

As Tony says - these are screwed down tight so no need to count turns.

 

Edit for spooling errur

Edited September 8, 2025 by Alan de Enfield

[nicknorman]

2 hours ago, blackrose said:

It definitely won't wiggle out. I haven't tried putting the carb in a vice yet and trying to tap it out with a punch.

 

On the other hand, some youtube videos I've just watched show a carb clean without actually taking the float off so perhaps I don't need to?

 

 

 

Just to be clear, the thing under the float tab is not a jet, it is a control valve that lets fuel in when the float level drops a bit, and stops fuel coming in when the float is at the correct level. I think it is fairly unlikely that this is blocked, and if it is the symptom is that the level increases too much and fuel starts coming out of the overflow especially at low power. The thing in the centre is the main jet, that is screwed hard down and might be worth removing for a good clean out but make sure you use a decent and correct-sized screwdriver as the brass is quite soft. However probably the more likely candidate for blockage is the idle jet etc (ie the smaller passages).

The other thing to check is the float level, ie the height at which the float shuts off the incoming fuel - which of course controls the level of fuel in the float bowl, which has an impact on mixture at high power. Probably in the manual somewhere will be a means of measuring that, typically from the carb flange to the top of the float (ie the top when the whole thing is held upside down with the needle valve held closed), and the tab on the float bowl that operates the needle valve can be bent slightly if necessary to achieve the correct shutoff height.

Edited September 8, 2025 by nicknorman

[blackrose]

Thanks Nick, yes I sort of knew it wasn't a jet but I didn't know what it was called. The symptoms were engine cutting out when increasing revs from idling and also dumped fuel out of the overflow.

[Tony Brooks]

13 minutes ago, blackrose said:

Thanks Nick, yes I sort of knew it wasn't a jet but I didn't know what it was called. The symptoms were engine cutting out when increasing revs from idling and also dumped fuel out of the overflow.

 

It is hard to see with OBs, but do you get any dark exhaust smoke just before it cuts out. If so, it might be that float needle valve.

 

The throttle cable turns the whole magneto baseplate, only opening the throttle by a cam on the baseplate, then test the resistance of the plug lead. Wire leads (unlikely) zero ohms, resistance leads between 5000 ohms and 1K ohm per meter. That movement can, over time increase it. 

 

Also check any other electrical cables for potential damage.

 

I think this may turn out to be a coil pack problem, especially if it gets worse as the engine warms up. 

 

Edited to add: what colour is the plug tip immediately after it cuts out, because if it is sooty it is fair indication it is that needle valve or float level.

Edited September 8, 2025 by Tony Brooks