Float Levels Confusing

[Norseman]

Okay, time to go back to the experts. The bike is a GS650GLX. I have the carbs off, cleaned, new o-rings/gaskets, bench synch'd, and getting ready to re-install. I thought I'd check the float levels, so I've read up on many posts, incl. searched.

Here is the conditions pre-work. Pipes are extremely (I guess that is in the eyes of the beholder) blued. Ran a rough idle and would die if left alone on idle, but the RPM was not too low (around 1200). Two carbs leaked gas like crazy from drain screws and bowl gaskets.

So I get the carbs off, and do the above. Now they are assembled back on rack, upside-down on level surface with bowls and gaskets off. I understand that I should measure from the gasket base up to the level area right where the drop-down is but before the float starts to curve. My Clymer says 21.4 to 23.4 mm (which seems to me to be an unreasonably excessive tolerance). Others on this forum say a nominal of 23.87mm, which is quite a bit more than the Clymer nominal of 22.4.

The other question I have is about the gasket base on the carb; there is a slight ridge (or raised line) running around the base, I assume for extra sealing properties with gasket. Do you put the caliper ruler inside, on top of, or outside this line? Or am I being completely anal about this?

Finally, the reason I mentioned the bluing and rough/dying idle is that when I measured my actual floats (yeah, I put the caliper on the inside of base ridge:-D), I measure 20.55 on #2, 3,and 4, and 20.05 on #1 carb. Could this have caused my bluing and idle problems (too lean), or at least contributed significantly?

Sorry about my wordiness, appreciate any advice.

Norseman

[Nessism]

I don't think fuel level in the float bowl will lead to running lean at idle since the fuel pick-up point is through the main jet which picks-up down at the bottom of the float bowl.

[Dave8338]

You can measure either inside or outside of the ridge on the carb base. Were your pipes blued before you started with the carb rebuild? Is your choke circuit working corectly? Are you sure the the idle circuits are clear? Where do you have the idle air screws set, they should be at 1 1/2 out from lightly seated.

[Norseman]

Thanks, Guys. To answer your question, Dave, the pipes were blue when I bought the bike in January. In terms of choke and idle circuits, there was some build-up, but really not bad. My o-rings and gaskets were in bad shape, but the circuits did not appear to be clogged or restricted (if I'm understanding "circuits" correctly).

Now, my idle air screws - that's an entirely different story. Two of them were only 1/2 turn out from bottom, and the other two took 3/4 turn to bottom out (gently, that is).

I'm not looking for a single source of problem, because I do think it is a multiple-issue problem, for instance, I bet when I check my valve clearances, I won't get the .03 feeler in one or more. I was just really surprised when I checked the float levels and found them so much off. If I'm understanding this right, floats that are too low (in the upside-down position) will cause higher gas level in the bowl, and now I wonder if that's where some of my gas leaks came from (or at least exasperated the condition?).

Finally, I'm still confused over where to measure on the float. When looking closely at the photo in Clymer, it looks like it is placed at the highest point on the float - the flat area just before the metal arm ends. Yet, I read different posts where it is measured at the flat area where the float steps-down. If measured at the top where the metal retainer arm ends, my floats aren't that much out-of-whack, and the Clymer nominal makes sense. If measured at the step-down, my floats are at 22.5mm, and I would have to bend the tabs a lot to raise the floats 1.3mm???

Norseman

[Nessism]

I don't have a 650 but rather a 550 with CV carbs which I think is similar to yours. Remove the gasket and measure from where it sits. Float must not be depressing the spring on the needle.

[Bud]

one thing for a really wierd set of carbs I have is to measure when it just hits the needle spring. Flip the carbs over and slowly tun them back, measure just after they fall. This should keep them from depressing the needle spring.