Siphon tube in the carb?

I'm now in the process of taking my carbs apart and making sure everything is done right (this time).

Took out all my jets, cleaned the center bore where the piston rides with 1500 grit wet sand (looks great), performed the Clunk Test and passed with flying colors. I still have to measure the dry height of my floats along with a couple of other things (found a nice post on cleaning out the enrichment circuit well that I'm gonna try tomorrow).

So I figured I'd take compressed air and blow out as many as the passages as I could. I did the first time I put it together, but I wasn't very thorough. Now, I'm trying my best to make sure everything is done right. I'd hate to put it back together and find out that they have to come apart again.

On the underside of the carbs, next to the floats is a drop-tube. I'm guessing it's used to pull fuel up during a choke operation. Is this accurate?

And if it is, how can I verify that tube is clear? Might seem kinda nasty, but as I'm sure my carbs are currently cleaner then most of the silverware I've ever owned, I put my lips on it and tried to blow through. Cycled the choke, cycled the throttle, and seemed like I couldn't get air through them at all. Am I heading in the right direction with this?

Thanks a ton guys. I'm off to bed, I'll check back in the morning.

 

If you're talking about the hole in the bottom of the bowl?
You need to have it so clean that carb cleaner shoots 6 foot from the other end.
Guitar strings are good for this, Chacal sells a drill bit of the right proportions also.

 

Same with the pilot fuel circuit.......it better flow clear and strong like the mighty Niagra.

ANY and EVERY small passage within the carb body, bowl, or any removable part (jets, emulsion tube holes, etc.) had better be zestfully clean or you'll just be doing it again until it is!!

 

Hound, he's talking about the siphon tube that goes the enrichment jet in the bowl.

And yes, clean as a whistle. But the guitar string won't make the bend after you go in the siphon tube, so you need to clear it with that first, then carb cleaner and compressed air will hopefully finish it off.

 

I know they have to be clean, which is why I'm pestering you kind folks. My question is the siphon tube. Where does it lead and how do I know it's open. When I get it clean, how will I know that I have a clear path? Do I open the choke up, or am I going in the wrong direction with that?

And what size is the drill bit? I probably have it at work.

 

The drill bit is almost like a human hair.

It was shipped to me in a plastic bottle so I could find it.

I used a waterpic to help clean mine out, before I got the itty bitty drill bit.

Remember to point the exit hole away from your face before testing the flow through the passage with carb cleaner.

 

If you reffering to the brass tube out the bottom of the carb body. That tube must be clean in order for your enricment circuit to work properly. Go by a welding store or I thnink Northern Tool if you have one in your area and pick up a tourch long tip cleaner set. Its a set of wires in a metal case. Use those to probe up into the carb body and just it open so you can spray it out good with carb cleaner and compressed air.

As far as tthe float bowl enrichment jets go. You can use the smallest wire in your tip cleaner set but it won't go through the jet. If the jet is too plugged you will need to order the special bit from Len to clear it out. Be carefull when spraying carb cleaner wear safety glasses and point the bowl away from you. When its clear it will shoot carb cleaner out about 10 feet.

 

A low E guitar string fits the enrichment jet just fine.
I will say, it won't DIG the stuff out though, if it is REAL clogged you need len's bit. Otherwise, a cheap low E string will fit it, and they are hard to find over 75 cents at any music store.

Probe the siphon tube/bowl jet.
The siphon tube won't let any probing tool go through because it has a bend. Just probe it from both sides (in the 'choke plunger well' there is a small hole on the edge, get in there too.)
Then just carb cleaner and compressed air till it flows free.
If you don't have an air compressor, just use the carb cleaner upside down.

 

"The siphon tube won't let any probing tool go through because it has a bend. Just probe it from both sides (in the 'choke plunger well' there is a small hole on the edge, get in there too.)"

Thanks, I'll have to find that other hole. That's the info I was looking for. Where does the plunger tube emerge? I'm guessing that means I have to dismount all the choke plungers, which is why I couldn't get air through the hole the first time, correct?

Thanks for the great responses, guys.

 

Correct

The choke car has to come off so you can remove the choke plunger valve.

Once in there with it all removed (retaining nut, valve itself, spring) down and off to the side there is a cutout in the corner on an angle, that is the place the fuel comes in.