Float needle clip?
I've got Bing CV carbs taken from a '84 R65LS on my '71 R75/5. I've had an intermittent problem over the last couple of weeks where fuel will suddenly start spilling from either one of the carbs onto my shoe as I ride. If I remove the bowl, tickle the float a couple of times, and put the bowl back, all is well until a few days later when it happens again.
I believe that what is happening is that the float needle is rotating around from vibration. When that happens and the fuel level in the bowl is low (the float needle is therefore out a bit to allow fuel to flow into the bowl), the clip sometimes rotates into a position directly below the main jet housing. Then, when the fuel level rises, the clip hangs up on the bottom of the housing, which prevents the needle from moving into the fully closed position. Once I tap it a few times, it moves away until the next time it slips in there.
1) What does the clip really do? It seems to just hang out there loose on top of the float needle without contacting anything else (except the main jet housing).
2) Perhaps I installed the clips wrong when I cleaned the carbs a while back. Is there some particular way to install them so they don't get hung up on the main jet housing? The way it stands now, the clip is not centered over the float needle, but sticks out to one side. When that side faces the main jet housing, it gets hung up.
Now I see that the clip is supposed to attach to the float, although the diagrams don't make that clear and the person who owned the carbs before me didn't do that. Sorry for the unnecessary thread.
Good that you've figured things out. AFAIK, the small spring clip is there as a positive means of pulling the float needle away from the gas inlet when the float drops. If it's restricting movement of the float or needle, then it is installed improperly.
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'78 R100/7 & '69 R69S & '52 R25/2
mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!
Yes, I wondered what the clip was for from the beginning, since it wasn't attached to anything when I disassembled the carbs. Carbs are somewhat of a mystery to me, so I just figured "Hell, it must do something!"
Years ago when I was first cutting my teeth on Bing's, when I got occassional unexplained overflows, I could always trace the behavior back to bits of crud getting stuck between the float needle tip and the needle seat -- something the clip could not influence.
I'd suggest looking upstream -- How old are your fuel hoses? (they deteriorate over time) When was the last time you checked/cleaned the tank screens? (are your even present, or did a prior owner remove them, letting any in-tank crud pass through the petcocks)?
Fuel hoses are new. However, the screens are not-so-new. I gave them a once over with some carb cleaner a few months ago when I was getting bike running. It's possible they're part of the problem.
For now, though, I'm going to assume it was the clips. It was a real mystery, but this morning, after the right carb overflowed, and I was doing the standard "flip-the-float-up-and-down-a-few-times" cure, the clip jammed the needle in the open position.
If the overflows continue I'll look further upstream.
I replaced a set of Mikunis with these because I wanted a more stock look. I have to say, after kicking one of the bowls off while riding, a slow leak from the left carb that looks like it comes from a loose spring clip / worn down bowl, and now these overflows, I'm beginning to question my decision.
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