Carb Rebuild And Parts

[BPT]

I'm going to get a rebuild kit and was going to go with the Motobins (genuine) version. This is about $53.  Mr. Tony Smith recommends a thorough overhaul and listed some pieces to get which I have some questions about.

Throttle shafts seals - Motobins doesn't break down what all of the o-rings in their kit are. Is one of those for the throttle shaft?



Tony also recommends replacing slide needles, needle jets, and float needles.  What of these are standard size or can they all vary?  By that I mean if you have a particular carb, should these always be the same or are these some that people will tinker with?   To make it a little more confusing (to me), I saw that one of these has a year specified and it splits in '83, which is what mine is.  So do I need to get VIN specific for that?

I was looking to get things ordered so I'd have it when I get time to take the carbs apart. But now I'm wondering if I need to have them apart to make sure I get the right parts.  Make sense?

My carb #'s are 64/32/335 & 336.

            Thanks

[BPT]

Sorry. Forgot the Motobins link:

https://www.motobins.co.uk/mobile/bmw-parts3.php?bikeref=R90-6&P=1&model=R%20Series%202%20valve%20Twin&M1=5&M2=700

[Bob_Roller]

Jets and needles are specific to a partic ular carb number .

The Moto bins kit, does not have the throttle shaft screws you need, if you are reppacing the throttle shaft seals .

[BPT]

Ok, that's good if they're specific to the carb, should make it easier. But how do I determine that?  I tried on the Max fiche but didn't get anywhere.

As far as screws - ok, I'll look for those also. But can you tell if the shaft seals part of that kit? Or do I need to get those separately?

I can't tell from the pic and I didn't know if those were considered a standard part of a rebuild kit or something extra since Tony mentioned them specifically.

[Barry]

Take a look here

http://www.bingpower.de/en/service/tuning-manuals/



64/32/335 - Vergaser 64-3      
replacement for      _
replaced by      _
similar to      _
engine model      R65-US USA 82_
      _
      _
stroke      4_
cylinder      2_
displacement      650_
carburettor body      13-306-32-010_
motor flange      50_
filter connection      43 spezial_
cover plate      _
screw cover      _
slide      22-907-131_
mixing chmaber insert      _
float chamber      30-559_
cover for float chamber      _
fuel connector      35-300_
float      _
slide adjusting screw      _
clamping screw      _
main jet      44-051/138_
spare jet      _
pilot jet      744-353/45_
starting jet      44-031/66_
idle air jet      _
correction air jet      151-421/1,05_
needle jet / mixing tube      45-196/2,64 / 45-425-101_
jet needle      46-251_
position (jet needle)      3_
float needle      47-968_
tipper      _
for after market      _
air regulation jet      50-028-101_
open      3 x_
float needle      51-536-25_
atomizer      51-590-1_
pipe bend      _
isolating bush      _
filter      _
additional information      ^

[Bob_Roller]

The Bing kit and the Motobins kit both have 5 o-rings per carb, so I think you're covered there .

I have a manual from Bing that has the needle and jet sizes for each carb, as it had when assembled at Bing .

I can post them this evening when I get home from work .

[BPT]

Excellent, thank you gentlemen.  I had some info like this saved before i actually needed to use it on my laptop that crashed.

Happy to see whatever you've got and will print some to add to the files.

I figured many here could tell by looking what all the o-rings were good for. But the variety of jets was what really had me confused.

       Thanks

[Justin B.]

The throttle shaft have O-rings as well as the idle/intermediate jet, enricher, and I forgot where elsewhere.  It'll be evident when you take them apart...

[BPT]

Yeah, Justin, I figure I'll learn-by-doing with this. But the way my brain works, I don't want too much of a gap between disassembly and reassembly, if you know what I mean.  So I was wanting to have all the stuff here ready to go, if possible.

As we talked about in another thread, there's a lack of places locally that we can just go out and grab things.  I know I can't depend on the only BMW dealer in the area.

[Barry]

List of O rings and sizes

Enrichener shaft       5x1.5mm
Main jet holder      8x1.75mm
Idle mixture screw      3x1.75mm
Idle jet      3x1.75mm
Throttle shaft      6x2mm

[BPT]

Thanks Barry!

[mrclubike]

 Make sure you understand how to set the float level
You set it without the spring being compressed
So hold the carb at an angle that the float just touches the needle but does not compress the spring

By going with MotoBins you will have the parts faster and with less hassle than going to your local dealer
Sad but true   

[BPT]

Yep, the Motobins price is cheaper than anywhere I've found for the genuine kit.  And I've been incredibly impressed (shocked?) at the speed of their shipping.  I get their stuff more quickly and for the same or less cost than I do most domestic stuff.  Amazing.

As Justin and i discussed recently here, the only "real" BMW place neat me isn't very good for old bikes. They're usually friendly enough but never seem to have what I'm looking for.  They will order but they're prices are always more than any other BMW places I see online.  I'm jealous of the people who can just walk into their local one and pick up basic things.

I'll make a note of the float adjustment you mention and add it to the list of things I need to learn.

       Thanks

[Justin B.]

I actually set the floats by attaching a piece of tubing to the inlet, blowing through it and pushing the float up until the airflow stops.  From there I adjust accordingly...

[georgesgiralt]

Hello !
Actually there are only two needle for the BMW used Bing (CV version). The first one covers all the carbs before 1983/84 when they changed the way the needle was held into the slide.
So for your particular carbs you need the correct needle jet size and a set of standard needles and either the rubber tipped float needle or the bronze tipped float needle.
If I'm not mistaken you can use the rubber tipped float needle on the old carbs.
Hope this helps.