Float level

[a101960]

I seem to remember reading somewhere about definative and accurate way of setting the float level on monobloc carbs using clear plastic tubing. Does anyone know what is involved? By the way I thought that I would just mention the excellent service that I have experienced from C&D Autos. Today I ordered some spares, and one of the items I wanted was ethanol proof fuel pipe. I also wanted a fuel pipe crimping tool which C&D Autos do not sell, but they are sending me the tool on loan that they use so that I can make up my fuel lines with proper crimps. How cool is that? Well done C&D Autos.

John

[chicago]

Hi there fella, all you do is get a piece of see trough tube(small enough diameter to fit snugly over the end of theidle jet), turn the petrol off on both tank taps, remove the screw on cap on the idle jet' put one end of the tube on the end of the idle jet, and place the other end next to the float bowl, turn the taps back on and you will see the petrol rise up through the pipe, when you look at the level of the petrol in the pipe it should I think be about level with the little dot under the amal on the float bowl.
Brilliant idea, can't remember who first posted the method on here but it's very clever. All the best fell, Chicago.
P.s I'm no expert so have somebody confirm this for you. :)

[a101960]

Chicago, Thanks so much for that. That is exactley what what I wanted to know. I am very greatfull for your answer. Cheers.

John

[chicago]

No worries fella  wink2, all the best, Chicago

[RichardL]

Hi guys. No need for me to start a new topic called "Float Level" since this one was here.

I am rebuilding my 930 concentric with the full kit from Amal and getting to where I need to set the float level. I suppose I could just do it with the float bowl off the carb and sitting level somewhere, or, I could use the clear tube method once assembled on the bike. I thought I might try something a bit different. Looking at the photo, has anyone tried this before? (...as a way to set float level. I know the bike won't run well like this.) I haven't tried it either, yet. So far, just the setup. The idea is that I will be able to measure down through one slot in the bracket. Oh yeah, not an expert in this task.

Richard L.

[bikerbob]

I don,t see why that method should not work seeing as the float needle on the concentric carbs is pointing up and on the monobloc pointing down. Just looking at an article about setting the float level on concentric carbs I quote, "Initial float level should have the rounded edge of the plastic float between .660" and .080" below the top edge of the bowl. Depress the  white tang that straddles the float needle and note the measurement at the opposite edge of the float. It should be approx .60" and .80" below top edge of float bowl. For those who would like to measure the gas level it should be between .170 and
.240 inches below the top of the bowl. When the float level is adjusted properly  you might have to adjust the float tickler assembly. Pull the roll pin out of the aluminium button until it depresses the float properly. " Hope this helps but I do not see how you would use the clear tube method on a concentric unless you just connect it to the fuel intake pipe and then pour fuel down it, but you would have no visible mark on the outside of the float bowl I suppose you could put a mark  the correct distance on the bowl .170 and .240 inches from the edge. I have no real knowledge of concentrics just looking at diagrams had a concentric on my A65 and it did not run or start very well but as soon as I replaced it with the correct monobloc all problems solved.

[muskrat]

G'day Richard.
I can see your reasoning for that rig, but can't see the benefit.
I use the clear tube method. Can be a pain to remove the bowl to adjust.
You will have trouble getting a good fuel height due to the slight downdraft of the alloy head manifold. About 0.300" below the carb/bowl joint. Any higher it will flood so I use slightly richer jets to compensate.
Cheers

[RichardL]

Muskratji,

Let me see if I understand you. Looking at the drawing (not to scale), am I correct that you are saying that the fuel level in the bowl needs to be below the low point in the intake manifold opening with respect to the tilt of the whole thing?

[muskrat]

G'day Richard.
It has nothing to do with the manifold opening. See new drawing. The way the concentric is designed if you try to get the 0.24" fuel level the float hits the roof of the chamber , holding the float needle off it's seat. I spent days and ruined two new stay up floats trying to get the fuel height higher with no joy. 0.3" was the best I could get. I've been told the Mk II concentrics can handle the downdraft angle better but I haven't tried.
Cheers