Servicing carburettor

[Fab1]

I'd like to share how I go about cleaning out Carburettors and what to look for for those having issues with them and are prepared to give it a go.

The first thing you want to do is remove the carburettor and set it aside on a clean work surface along with the tools you'll need.

I'm using a clean towel as a work surface.

Carburettors come in different configurations such as 1 barrel 2 barrel etc but they rely on the same principles for operation.Ill be demonstrating on my 1 barrel carby here which is pretty much as basic as you can get.

Keep in mind your working with cast alloy and brass and you don't want to over tighten screws jets etc as you will break,crack or strip out the threads and parts.Just do things up snug and you'll be right.

The first thing I do is drain the fuel out of the bowl into a clean container to check for water in the fuel and debris floating around in there.All good on both counts.

Next I remove the fuel bowl to get access to the needle and seat,fuel bowl and jets.

Then I remove the float from the bowl with the needle attached.

The float and needle removed from the main body of the Carburettor.You want to inspect the float for rupturing or split seams which will allow fuel to enter the chambers displacing the air inside giving you incorrect fuel levels in the bowl.Also ensure the needles tip is nice and pointed as when they wear they will not seal against the seat and the bowl will overfill.

The needles seat has a tiny hole drilled through it which must not be blocked with debris(Hard to see on photo).

Now I'll remove the main jet.

Here its removed from the carburettor,again you want to make sure all the holes/passages are clear.

There's in last jet hidden under a rubber plug.

Remove this jet also.

You've now pretty much disassembled the carburettor as far as you need to and should have the 2 jets,needle and float removed.hi

I have a selection of copper wire I use to clean the passages and holes in Carburettors combined with spraying carburettor cleaner and compressed air through all the orifices and passageways in the carburettor.

Here I have cleaned all passageways,jets and the carburettor itself as described above ready for assembly with all the parts organised and laid out in the order they came out.

Carburettor being assembled in reverse order.

Your goal after assembly.No parts left.

Time to fit the carburettor back on the motor.

Hey you can see the read valves through here.

After fitting carburettor and a few linkages back she's all finished.

Cheers.

[MV Sunray]

Your tutorials are a good read on wet rainy days. Thanks for taking the time to do so. Maybe some never seize on the brass threads when re assembling?

[Fab1]

Your tutorials are a good read on wet rainy days. Thanks for taking the time to do so. Maybe some never seize on the brass threads when re assembling?

Im glad you enjoyed it as I don't like to sit idle in bad weather and take the opportunity to do maintenance and things around the place.I don't use anti-seize on carburettors as I find it's not needed.

[JA1990]

Looks like an interesting project but do you need to replace gaskets?

[recurve]

I did this once on my 140 V4 Yamaha 2 Stroke. I was bricking myself but I managed to take it apart and put it together with no drama.

I had issues with the throttle and was told I had water in my Carb. Turned out that was not the issue and I had 3 hours of stress taking it apart cleaning it and re-assembling it .. However a good learning experience.

One thing I could not do was tune it nicely once I had taken it apart. I thought I had but after it went to a Marine Mechanic and he tuned it, it was a different motor.

[Fab1]

Looks like an interesting project but do you need to replace gaskets?

If you break them you do.It's best to rebuild with a gasket kit but it isn't necessary if the existing ones are in good nick and you don't break them when dismantling the carb.