Emulsion Tube Removal

My bike seems to bog down when you open the throttle quickly. I've stripped the carb and put it in my ultrasonic bath but I didn't remove the emulsion tube as I wasn't sure how. Is it just a case of removing the main jet then pushing it down and out from the bottom? Or does it push up out of the top of the carb? Carb is the original 18mm Mikuni.

Also, what's the best setting for the mixture screw? I'm currently 2 full turns out.

Bike behaves fine when revs are slowly increased.

Thanks in advance.

Probably accelerator pump piston stuck, best to get a Haynes manual it covers the carb & gives settings etc. Mixture screw should be adjusted till it gives even tick over.

The pump works fine, might hold the linkage and try it without tomorrow just in case it's getting too much fuel. I have a Haynes manual coming just thought it would be worth an ask as I'm sure one of you has had the emulsion tube out before.

Not sure what you mean by 'emulsion tube', there is no such named part in the carb diagram in Haynes. If you are referring to the brass tube in the float bowl this is an overflow tube for excess fuel. It has no bearing on the carburation.

The emulsion tube is above the main jet, it's what regulates air to fuel mix leaving the float bowl. The tapered needle on the plastic piston slides up and down it. If you remove the float bowl and turn the main carb body upsidedown you can see 2 jets, main (larger diameter) and pilot. If you remove the main jet there's a brass tube in that hole. That's what I'd like to remove.

I've never heard it called anything else but you live and learn.

Here is a link to carb exploded drawing, https://www.ajsutton.co.uk/genuineparts/9063/7/yamaha-t80-townmate-1986/carburetor?uID=0 but it does not say how to dismantle it, you will need the Haynes manual for that, frankly I have never needed to take mine apart other than clean the float bowl. The 'emulsion tube' listed as Nozzel Main is unlikely to be blocked & and a blow through with an air line in situ should be sufficient.

Hi, I also have carb problems. Mine is a mystery spring which resides somewhere in the vicinity of the throttle valve assembly. I have posted a request for information on this forum. Regarding the Haynes diagram and others, they are somewhat short of detail and do not show all of the internal components. The emulsion tube being one and my spring another. I have been told rightly or wrongly that the parts omitted from the drawings were never available as spare parts, therefore if there were any problems the whole carb assembly had to be changed. Perhaps there is a member of the forum, who knows if this is correct?

Chouse wrote:The emulsion tube is above the main jet, it's what regulates air to fuel mix leaving the float bowl. The tapered needle on the plastic piston slides up and down it. If you remove the float bowl and turn the main carb body upsidedown you can see 2 jets, main (larger diameter) and pilot. If you remove the main jet there's a brass tube in that hole. That's what I'd like to remove.

I've never heard it called anything else but you live and learn.

hello, i m late but i remove this tube as he does at this video:

https://www.youtube.com/watch?v=EzZ9ZzRzrmY

before I tried, I'd drop a lot of WD40 to make it easier. Ιt does not need much strength, just  a small but decisive hit so it will not be destroyed.
I have cleaned the carburetor  many times but I did not think that I would find so much dirt and residue from the fuel there.
You can see the dirt at the photos:







More than half of the holes were blocked and I had to clean them.
I do not know how important it was and how much it affected the performance or the behavior of the engine.
I cleaned them as best I could as I placed them back.