Excess oil

[stefanoascari]

I'm sorry. This seems to be going way over my head at the moment. Is this something that the carb cleaning walk through in the FAQ covers?

[txbanditrydr]

Lots of folks here eager to help out.....   clarify your concerns and we'll attempt the same.   

[stefanoascari]

Ok. Sounds good!

I have been able to detach the throttle cable. It's a bit of an odd place to reach around and grab. Putting it back will be fun. The carb set is now sitting on my desk. I will go purchase a carb kit and cleaner tomorrow.

[andrewsw]

"Now, people will tell you that you have to be very careful to hold the carb at 45 degrees so that the float doesn't compress the needle spring. But, on the B4, the floats aren't heavy enough to do this"

Not true, I had this exact issue the first time I rebuilt my carbs.  Maybe different floats weigh differently but mine compressed the needle springs significantly.

On a B4? Interesting. This is the second one I've owned and third set of carbs. On all of them the floats have not been heavy enough to move the needle springs under their own weight. But then maybe I'm doing it wrong....

That said, I've seen other carbs on other bike models that *definitely* move the needle under the weight of the floats and one has to be really careful when checking this.

I'm due to pull them this weekend and I'll take some photos of how I make the measurement. I'd love to learn that I'm doing it wrong, if that's the case!

A

[stefanoascari]

Ok. So I started opening up one of the carbs. How do I remove the float needle? It all looks so fragile I'm scared I'll damage something.

[andrewsw]

It's not quite as fragile as it looks.

you can remove the entire float assembly by lifting it straight up as one unit. It should be wedged in a little tightly by the o-rings that are in there (you'll see them after it comes out), but just pull. It will come out. You shouldn't have to actually remove the float needle from it's housing (part of the whole plastic float assembly) unless something has gotten stuck down in there.

A

[stefanoascari]

Ok I was able to easily remove the float assembly. For some reason I thought I was supposed to pull the needle out too. Note of the floats look "stuck". I'm not sure what I'm looking for. The needles seem to work. If I'm not pulling the float needle out what is there to adjust when I'm re-assembling? This part is the only part that is confusing me so far. It looks like they just clip on. In all the tutorials I've found however people talk about measuring the height of the floats to the gasket base. I get that. What I don't understand is what exactly needs to be tampered with to set this height?

[andrewsw]

there's a flat metal "spring" that is connected to the floats and engages the float needle. This flat bit of metal is what you adjust.

A

[stefanoascari]

Ah! I see. It's like a thin wire right? Do I use pliers to compress/adjust it?

[andrewsw]

The thin wire, which should form a rectangle is *not* the thing to adjust, but instead the metal tab that it wraps around. I'll try to get pictures tomorrow.

A

[stefanoascari]

Ok Cool. I think I know what you mean. As for the float needle inspection, I notice these don't have rubber tips (they seem "bare"). What should I be looking for? The springs seem to pop back ok.
Perhaps I should purchase replacement floats for all the carbs to be safe? EDIT: It would seem I DO have to take the float needles out for inspection. Is this correct?

Thanks for all the help by the way!  

[andrewsw]

Usually, if there is junk in there you can see it without actually removing the float needles from the assembly. honestly I can't remember if there are rubber tips on there or not. sorry.

Planning to tear into them tomorrow for my own work. I'll post pictures with arrows and such :)

A

[stefanoascari]

Ok great. Thanks andrewsw. Also, a few other things:
- I can't get the emulsion tube out from the main jet. Are they supposed to fall out?
- I'm trying to understand how the floats interact with other components in the carb to stop fuel flow. As it is, it seems like they are simply there to float up and down but aren't connected to any other components. Am I not seeing something??

[andrewsw]

Okay, here are some photos.

They show the height adjusting tab for the floats. You just press on that a bit and it will adjust the height. They also show how you can measure the float height using the cross-member on the float assembly. If you look, you'll see that the assembly height from the gasket surface is 24mm. so for 15mm float height, measure down 9mm from the cross-member. Pretty straightforward.

Finally there is one showing the spot where stuff get's stuck forcing the floats to stay open.

I did experiment with my floats and confirm that *on* *my* *bike*, the floats do not cause the float springs to compress under their own weight, making it easy to measure them. Your mileage may vary.

- I can't get the emulsion tube out from the main jet. Are they supposed to fall out?

To remove the emulsion tubes, first remove the tops from the carbs being careful not to loose the tiny o-rings around the vacuum ports. Carefully lift out the spring, slide and needle -- watch out, lots of small bouncy parts. Flip the carbs over and remove the main jet. using an appropriate tool and care (brass parts!! Soft!! Be careful!!) press out the emulsion tube. The main jet screws directly into the emulsion tube, which is press-fitted into the plastic slide carrier. It should come out with a light tap or two. It may instead push out the slide carrier itself. This is fine, with that out, you can easily tap out the emulsion tube.

- I'm trying to understand how the floats interact with other components in the carb to stop fuel flow. As it is, it seems like they are simply there to float up and down but aren't connected to any other components. Am I not seeing something??

Hold the float assembly right-side up. The large of the two o-ring areas fits into the fuel inlet. When the fuel in the bowl is low, the floats fall down letting the float needle, sitting right under the float needle orifice (see the picture showing where stuff gets stuck) lower to open the orifice. Fuel can then flow into the float bowl. As the fuel level rises, it lifts the floats until they press on the float needle pushing it into the orifice and stopping fuel flow. All the rest of the fuel metering is done from the float bowl itself using the pressure differential between the engine and air filter sides of the butterflies and slides.

Hope this helps.

[andrewsw]

the other two photos...