The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Bengt_Phorqs on March 16, 2010, 01:16:19 PM
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Do the two holes on the bottom of the Bing Type 64-3 carb slides face toward the cylinder (forward) or to the air box (rear)? Inquiring minds need to know this.
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I've wondered about that myself, and I've installed them both ways, and didn't see any problems either way .
I'd go out on a limb and say it probably doesn't matter, as long as the holes are open .
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If my memory is correct...isn't there a tab on both the inner and outer lips of the diaphram that line up with corresponding indentations in the top of the slide and carb body for each? So there's only one way it can go back together? My carbs are still in a bag, if needed I can pull the covers and report back.
http://i428.photobucket.com/albums/qq8/gruntyman66/81%20R650%20Restoration/Bing%20Carb%20Right/81R65RestorationBingCarbRt016.jpg
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There are tabs on the inner and outer edges of the diaphragms, I just checked an old set I had .
Looks like if you pay attention, there is a right and wrong way to to install them .
The inner tabs were indiscernible on the original diaphragms on the '81 R65, when I took them apart .
So I know I've had them installed incorrectly at least one time .
Been three years since I've had the diaphragms off for replacement on my carbs, I'm really rusty on them obviously !!!!!
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They face towards the cylinder.
I checked mine for another member about 2 months back and then confirmed that was correct on Snowbum's site.
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I'll take a look at both carbs when I get home tonight and report back. And make a note in my photo archives for future reference.
I have nothing else to do...still waiting for heads and jugs to return. 4 months and counting. Grrr.
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Correct on the diaphragm tabs, however because they attach by 4 screws on top the slide could be reversed 180 degrees. I'm pretty sure that the holes face forward also. My problem is that the left slide is sloppy loose in the carb body, and the right side slide feels overly tight. Hans at Hucky's Spare Parts suggest I swap slides from side to side to see if that sorts out my idle issues.
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When stripping the carbs for the first time I committed the cardinal sin of doing both at the same time and finished up not being quite certain of which slide went in which body. I thought I got them right but just in case I swapped them side to side and couldn't tell any difference in fit or performance. Mine are flat top though and must have been designed to be interchangeable as only one part is listed for both carbs.
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Rebuilt the ones on the 45 two days ago, but mine are the type that you have to pry off the red plastic retainer ring at the top of the slide.
Warmed it up with a blow dryer, and they popped right off.
My problem now is the needle that is in the slide has about 6 possible positions to be in. (Several 'notches' cut into the top of the needle).
I think my left side one is too 'high' as when I open up the petcock, it piddles fuel out the overflow hole at the bottom of the bowl.
~sigh~
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DeeG, when I get home from work today, I can look up what position the needles are supposed to be in, courtesy of the manual from Bing, unless someone else gets to it first .
All I need, is the numbers stamped into the flange at the front of the carb, should say something like : 64/26/*** .
R45 carbs should be 26 mm .
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DeeG
Bings German web site says position 2 for the needle. If you have flat top Bings it may differ and may also have varied for other markets.
It's a usefull web site though. http://www.bingpower.de/english/service/einstellblaetter.html
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Do the two holes on the bottom of the Bing Type 64-3 carb slides face toward the cylinder (forward) or to the air box (rear)? Inquiring minds need to know this.
Phorqs,
Snowbum's Bing overhaul info pages states the slide is to be installed with the holes in the bottom of the slide facing forward, towards the intake/cylinder head.
And...
DeeG says, My problem now is the needle that is in the slide has about 6 possible positions to be in.
DeeG,
28mm 64-2 flat tops or 28mm 64-3 domes, Bing manual states same clip position- #2 from the top.
Monte
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I've got the Bing manual, but I guess I didn't look carefully enough at it. I didn't realize until AFTER I had pulled the danged thing out that it was notched like that. grrrr....... I did look at the other one (which was still together) and tried measuring the needle from the opening of the slide to the end of the needle, but apparently, that didn't work. hehe
Funny thing is, the right side isn't leaking. Wonder if it was set properly or if there just isn't any fuel getting to it yet.
And yes, mine are 'flat tops'.
Now that the sun is out (well, its daytime anyway), and I've had a couple cups of coffee, I'll head down to the garage and see if I can't get the beast running.
I'm hoping this goes well, I've got to completely redo the carbs on the R75. They leak, and they look horrid.
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DeeG says, My problem now is the needle that is in the slide has about 6 possible positions to be in.
DeeG,
28mm 64-2 flat tops or 28mm 64-3 domes, Bing manual states same clip position- #2 from the top.
Monte
Thanks! Easy enough to do, two screws on the cover and the slide comes right out. I don't even have to remove the carbs. yay!!!
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I think my left side one is too 'high' as when I open up the petcock, it piddles fuel out the overflow hole at the bottom of the bowl.
If your carbs ore overflowing, the problem is most likely with your float needle either not seating due to wear or due to a bit of junk lodged in the jet, or maybe the float setting needs adjustment. Wouldn't think that the needle jet would cause a leak.
John M
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[smiley=thumbup.gif] 2x on John's thoughts. Quite likely. Monte
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Talking about carbs, I rebuilt them over the weekend only to find that the first one was installed with the little needle 'safety pin' not hooked to the float tab. Does anyone know if this matters?.
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Most definitely. That little "safety pin" is the only connection between the floats and the gas inlet needle. When the float level drops it allows more fuel to enter the bowl. When the floats rise it shuts off the fuel.
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Talking about carbs, I rebuilt them over the weekend only to find that the first one was installed with the little needle 'safety pin' not hooked to the float tab. Does anyone know if this matters?.
The physical connection is to insure that the needle is drawn down as the float drops.
Monte
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Thanks, maybe I can remove the bottom sink and insert the pin without removing the carb.
Will start it up tomorrow...