BS34 question

billyb

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Doing a rebuild of the carbs on my 81 special and while blowing out air and gas channels I happened to see a very small spring and a small bearing I mean small 3mm. Now I have worked on a few carb clean and rebuild in my day and can't recall seeing these parts anywhere before. Could these have come out of the BS34 or is it some misc shit I collected on my bench over time. I have looked at a Mikuni BS34 scematic and can't find these tiny parts. any input is greatly appreciated.
I also located another tiny spring but not the bearing laying beneath the other carb.
 
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Parts 47 and 48. Only found on BS34s with the hand-operated push-pull choke rod, as opposed to the cable-operated rod on later models. The rod has dimples that the ball bearing "stops" at.
 
Put a grease zerk in your drill press vice and drill out the ball bearing and spring. They work great. Did this to rebuild a buddy's BS34's. He had lost the ball bearing and spring without realizing they were there when he took them apart.
 
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Put a grease zerk in your drill press vice and drill out the ball bearing and spring. They work great. Did this to rebuild a buddy's BS34's. He had lost the ball bearing and spring without realizing they were there when he took them apart.
Thanks for the tip, robinc I will give that a try if I can't locate another bearing or find the original. I did the same thing took them apart and didn't realize they were in there till the 2 springs and one ball were laying on my bench and thought where the hell did they come from.
 
Nother tip. When disassembling carbs and other things with those tiny parts. Take em apart on a cookie sheet, catches the little bits. ;)
 
You really only need one spring and ball bearing combo. One is plenty. I fact, I prefer one -- it makes it easier to feather in-between the dimples when an in-between position is what the warming-up carbs call for.
 
I went thru this on the BS34s on my Kawasaki. I ended up ordering 10 1/8 ball bearings. I can send you one if you need it.
Here's a tip. Put them in the freezer until you are ready to install them and they drop right in.
 
I went thru this on the BS34s on my Kawasaki. I ended up ordering 10 1/8 ball bearings. I can send you one if you need it.
Here's a tip. Put them in the freezer until you are ready to install them and they drop right in.
Thanks for your generous offer XSguy but I did find the missing bearing so I am good to go. Nice to see people on this site willing to help. I have been a member here for a few years and am working on a total rebuild of a 81 special it is close to complete and will be a kinda scrambler/tracker look. I am a long time rider but this is my 1st custom build. Since retiring a few year back restoration and rebuild projects now keep me busy and I am enjoying working on these old bikes.
I am some times reluctant to ask questions before much research in the tech section because some members get ripped a new one for not doing so.
 
Quick little side ?. Can I replace my bs34s brass floats with plastic floats from later bs34s?

1st time working on my bike I didn't know the carbs can be worked on as a set. I tried to separate them and cracked the housing that holds the ball for the choke rod detent. I use a mini spring clamp now.
 
They say you can, but I would only use real ones, not Mike's knock-offs. The real ones have a sleeve inside the pivot so it fits nice and snug on the hinge pin. The repros don't have that and are a loose, sloppy fit on the pin. That can cause problems as they jiggle around so much they don't meter the fuel very consistently. Sometimes they work fine but other times they hang up or stick.
 
Yes you can use the later floats. Just remember to adjust them to the proper level. It is different than the brass. I do not have the manual handy to tell you what it is.
 
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