A journey through a hanging idle.

Wow, lots of information in here over the past few days.

K-Moe. Yes, my carbs were aligned properly on a thick piece of glass when I put them back together. When they're off the bike, they do slam back down, with the vigor of a mousetrap.

Dragsta: Tank is not stock, and petcock is completely gravity fed. #3 vacuum has been plugged.

Let me ask you folks this: Has anyone found cheap solutions for Vacuum port plugs? Though I haven't done the propane test yet (Waiting to set fuel levels before putting the carbs on the bike).

Since I'm setting the fuel levels, I figured I might as well start over since I do have the colortune and know that my jetting should be sufficient (though I'm going to order some extra sizes to have handy for the future). Went ahead and E-mailed hogfiddles to get one new valve shim while I have the valve cover and tank off and am learning to properly set the floats for the fuel levels.

I'm having a difficult time figuring out if my fuel level setup is correct. Does my tubing position look correct? Because you can see a small mark I made on the carb, 3mm from below the lip of the carb (marked while bowl still attached to carb body), and you can see that the fuel level in this tube/carb is quite a bit below it. I think I've got the hang of how to do it properly thanks to the DIY but just wanted to check if the procedure looks right before I start bending the tang.



Thanks.

 

Your setup is good. Your local autoparts store has vacuum port plugs.

 

you should stop right now and take all that gas and carbs and rags with gas outside before you launch yourself over to Lawrenceville.

 

test the level of carb 1 against carb 4 to insure left right level.
I do see a fire extingusher in the back ground as well as a radio controlled airplane.

 

..and a natural-gas furnace.......

and a shop vac, and a great big likker bottle like grandpapy used.

 

YOu should not have an air bubble in the test tube. I'm not sure, but I think there is one in yours, it'S hard to tell on your first picture

 

Your set-up and method is exactly correct, the fuel level is way too low (will run lean).

 

Thanks for the input guys, and good eyes all around. As for the natgas furnace concern: I have two rather large and powerful fans blowing out the door when I'm using flammable chemicals, and have an extinguisher as well. Caused me no issues last winter. That said, The most gas I've had in the basement was just enough to complete this exact process and or start the bike.

Luckily the furnace isn't even on yet...but that'll change shortly

 

Len can you explain? Thanks

 

I used blue windshield washer fluid to check the bowl levels on the bench. No smell and no danger. Downside is flushing it all out when you are finished.

 

Fuel level (bottom of the fluid surface, not the curved up edge) should be 3mm +/- 1mm from the edge of the carb body (gasket face). Yours looks lower than that.

Also, while the slides should drop smoothly and "clunk", they should free-fall. For instance, on my Virago, I had once carb where the slide dropped instantly, and the other one was noticeably slower. I thought the slower one had a problem, but, in fact, it didn't - the diaphragm had broken loose from the slide in the instant-drop one.

 

The bigger downside is a significant difference in specific gravity. Recheck and you'll find that your fuel levels aren't the same as they would be when using gasoline.

 

The clunk test is normally done with the carb hat removed so the diaphragm is not in operation. This also makes it easier to perform the test while polishing the slide (if needed) without having to fully reassemble each time.

 

Well, as with most things relating to the bottom of the carbs, things are "backwards". The physical fuel level is TOO LOW in the bowl, thus the fuel LEVEL MEASUREMENT will be too LARGE (a higher number), since the MEASUREMENT is done from the base of the carb body (where the bowl snugs up into the bottom of the carb base).

LOW physical fuel level in the bowl = HIGH fuel level measurement (lots of distance between top of bowl and level of fuel)
HIGH physical fuel level in the bowl = LOW fuel level measurement (not much distance between top of bowl and level of fuel)

A LOW physical fuel level in the bowl (= a HIGH fuel level measurement or distance) means that for any given amount of venturi vacuum available (acting upon the fuel), some of that vacuum energy is going to be used to suck the fuel up a GREATER DISTANCE than the fuel system designers had in mind.......thus not as much fuel will be made available to the main or pilot fuel circuits = a lean condition.

 

The phrase "from the gasket surface" confuses me. Therefore I've taken pictures of several possible ways that myself (or anyone) could interpret that. Disregard the very sloppy "3mm" I measured with a sharpie on the business card. In doing the procedure I'll be more precise.

1.) the way shown in above posts where I measured 3mm below the top edge of a business card, and simply placed it against where the carbs meet the bowl while the bowl is assembled

2.) with the bowl off, at the top of the gasket surface

3.) At this point, whatever you may call it (could potentially be same distance as option 1)

4.) By taking bowl off and measuring from behing the lip where the top of the bowl would mate within the lip of the carb body (this could potentially be the same measurement as option 2).


And for good measure, here are two videos: One is how my slides will slide with the carb hats on (slower, and not very clunky due to the vacuum).


The other I have titled "mousetrap vigor"

 

the first picture is right, the clunk looks good and the throttles sound right. Now note the butterflies after you snap them, then try closing them very slowly and see if they stop the same place

 

I tried that and it just plain and simply did not work because gas and washer fluid are different specific gravity properties

 

I don't believe that the first pix is quite right.......my understanding is the 3mm is measured from the bottom (base) of the carb body WHERE THE BOWL GASKET WOULD SIT (but w/o the gasket in place). That's about an extra 1mm or so in "depth" up into the body. The small "lip" or flange on the base of the carb body overhangs the face where the bowl gasket would sit.

Pix #4 is correct, and pix #2 is close except for the fact the the gasket gets squeezed a bit thinner when it is installed (screws) onto the body, so it's not quite as precise a measurement.

Pix 2 would be the same as Pix 4 if you removed the bowl gasket and measured off the top flat face of the bowl.


EDIT: I screwed up, Polock is right (as usual) and Pix #1 is correct!!

 

I've always measured like pic #1.

Gary H.

 

Me too; based on the float height measurement being made from the bottom of the carb body (the gasket surface) as well.