The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: BPT on September 14, 2017, 11:39:39 AM
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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
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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
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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 .
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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.
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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 ^
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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 .
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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
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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...
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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.
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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
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Thanks Barry!
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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 :o
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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
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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...
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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.
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Before you remove the jet needles measure how far they are sticking out
To remove them you twist them 90deg back and forth as you GENTLY pull them out
It is amazing how little wear in the jet and on the needle effects mixture
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It is amazing how little wear in the jet and on the needle effects mixture
Amen to that.
And it sometimes so bloody difficult to convince people that is their problem.
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Thanks again. Any and all tips and tricks are appreciated.
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Finally have time to post the various parts for your 64/32/335 - 336 carbs .
Main jet : 138
Needle jet : 2.64
Jet needle : 2.51
Atomizer : 591
Idle jet : 45
Also removing the needle from the slide, there are two versions as has been mentined .
My '81 R65, has the older version, a spring clip in the slide, twist and pull the needle out .
The later version, has a metal threaded ' plug ', you put a regular screwdriver down the top of the slide and remove the plug, then the needle comes out, there is clip on the needle that you set to the third position from the bottom .
Both of my LS's have this version on the 64/32/335 - 336 carbs .
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Thanks Bob. That'll save me a lot of time deciphering things. I can't remember what piece it was that I saw the split year for but now I'm wondering if it was the needle you're talking about with two different versions.
When you say your 81 has the earlier version, are the carb numbers the same?
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No, the '81 has 64/32/325 - 326 carbs .
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Ok, thanks. I was just wondering if I might need to plan for a surprise when I open them up. I'd hate to get stuck because I have one piece wrong.
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I've just overhauled my carbs, so while it's fresh in my memory I recommend:
If the bike is running, spray some brake cleaner at the throttle shaft on the engine side, if there's no increase in revs you can save some time and not bother dissembling the throttle shaft as I found those o-rings were still in top shape (replaced anyway while I was there) and I've read a couple of times that these o-rings last a long time.
Still check that the butterfly valve is on the correct way though, see this link by Snowbum which has photos of how it should be (and it's good to read through before you start) -
http://bmwmotorcycletech.info/bingcv.htm
Try and loosen the two carb top screws and four choke body screws on each carb first before the final order of parts - you may have a seized screw that is or ends up unusable again.
The five (each side) o-rings are: largest on the venturi, second largest on the throttle shaft, third largest on the choke shaft and the two smallest o rings are for the idle jet and idle mix screw.
I think you've got the Clymer manual - use that to find the order of doing things, it's pretty clear.
You can expect to take at least a day to take the carbs off, pull them apart (I recommend doing one at a time so you don't mix up parts), clean everything, put them back together and put them back on the bike.
Have a couple of cooling beverages after cleaning the parts, this is the most time consuming part. Assembling the carbs is pretty straightforward and by far the most fun part!
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Thanks Tunnelrider. I'm going to order parts in the next day or so. Then I'll be tearing into these. Ugh.