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Bing Type 53 Idle

JohnW67

Scraper
Hi,

I'm trying to get my '76 R60/6 to idle. The last few times I've fired it up, it will run rough with the choke on and smoke a bit more out of the right pipe. After it warmed up, the idle was around 500rpm. I tried turning the stop screw to the right, but it just got worse and now it is to the point where it won't stay running at all.

I know that the idle mixture screw should be set to 1 turn from my searches here. The carbs were rebuilt by Bing about a year ago. The whole thing started when I had to replace the points and reset the timing. The timing was set about a week ago and it ran quite well then and idled at about 800ish when relatively cool and up around 1000 when fully warmed up.

My question is where should I start with the throttle stop screw so I can get the bike to idle at all, let alone make the necessary tweaks?:hungover

thanks in advance!

John
 
I have a 60/6 that has given me no end of trouble to idle correctly...:D

There are two separate yet inter-connected things with carb setups: idle speed/mixture, and balance.


Idle: The idle stop screws are the big ones, they act like a wedge to hold up the slides. I have found it best to roll the throttle on just a bit while I turn the idle speeds, then let it down to check it.

I have also found that I need my idle mixture screws out at about 1.5+ turns. On the 53's, the idle mix is the AIR (not fuel), so turning it out gives it more air=less rich.

The "proper" procedure is this: slacken both throttle cable ferrules first. The idea is to not have any interference there, and to set the idle speed solely with the idle stop screws. Adjust both speeds, then the mixtures (you are looking to get the maximum speed from each carb), then go back to speed. All of this is best done with some sort of balancing "tool": either a vacuum tool (hard to do with these carbs), a flow tool like the twinmax, or by using the "shorting" method. I use the shorting method: you short one plug while you adjust the idle on the other, using the tach to keep them close to each other.

Once you are satisfied with the idle, that it is at a good speed, then you balance the carbs.

Balance: turn the ferrules down to where they take up virtually all slack, but still just a touch loose. Then balance the carbs at a speed above idle, say 2-2500 rpm: the idea is to get the cables to be pulling evenly i.e. carbs are balanced. Using the shorting method: short one side, note the engine speed, then short the other side, and compare the engine speeds. Remember that you are working on the carb that is NOT shorted: for the slower-side carb, turn the ferrule OUT until it is the same speed as the other side. This pulls the cable a smidge to bring it up to speed. Re-check and fine-tune as necessary.

Should be good to go.


Oh, and one other tip: those chokes can mess everything up! Make SURE that the chokes have some slack in the adjustment ferrules. I went round and round and round, over and over, trying to adjust my idle, my running mixture, etc, before I realized that my chokes were throwing everything off......:cry

Good luck! :D
 
Good write up on the process... :thumb I would suggest one thing on doing the adjustments for balance at speed. Rather than adjust the carb that is running slower, do the adjustments on the carb that is running faster. If you adjust the slow carb, you run the risk of reducing all the beginning slack which now affects the idle speed. If you adjust the faster carb, you're adding slack which then can't affect the idle speed.
 
i've found that when using the shorting method, you will have to increase the idle speed on the running side quite a bit to get it to idle so as to do the a/f idle setting. i tune by ear- fastest smoothest idle is what you're trying to find. then switch to the other side, repeat procedure over there. the idle speed will now be a bit too high, so turn down each idle setting equal amounts (maybe 1/4 turn or so). Now for the TwinMax or manometer to get them both dead on to each other. by this time, your engine will be fully warm... should be good to go.
 
+1 on everything rpeckham136133 said. I also ride an R60/6 and it took me a while to get the carbs sorted out and balanced after a rebuild. Problem: not enough slack on throttle and choke cables. No matter what I tried, I just couldn't get them right. After I figured that out, balancing was a breeze. Shorting method works like a charm!
 
What I like for the final go round after sync is to go back and bring the idle down so that when I pull the plug to short it, the engine will run maybe 3 or 4 revolutions and then die. I do the same thing on the other side, which results in an idle that is 700 or so.........Really nice.......

By the way, before you begin all of these carb adjustments, make sure you take the bike for a 10 to 15 mile ride in order for it to be warmed up properly. Otherwise if you use the idling/adjustment to warm it up, when you do ride you will find the idle is off........Good luck.......Dennis
 
Thanks for all the great detailed advice guys! This will focus my efforts for sure. Hopefully with some perseverance I can get the bike to idle long enough to follow through on your advice!:violin
 
It hasn't apparently been mentioned yet, so here goes: remove the carburetors and disassemble them (one at a time so you have an assembled one to refer to). Clean with carburetor cleaner. Go to hardware store, purchase a "welder's tip cleaner" kit for about $5. This is a set of little mildly abrasive wires. Use the tip cleaner to clean out the two little idle circuit holes which you'll find inside the carburetor body where the carb piston rides up and down. Spray the two little holes with carb cleaner. Reassemble. Test for improved idle.
 
I deleted a mis-guided post earlier today. However, I would point out that a correct valve tappet adjustment is essential to setting your carbs and acheiving stable idle.
 
...just curious, are these Bing type 53 (sliders) or 32mm CV carbs? If I took a guess at what would be on an R75/6 I would have said probably 32mm CV carbs, but I see Type 53 mentioned here too.
 
...just curious, are these Bing type 53 (sliders) or 32mm CV carbs? If I took a guess at what would be on an R75/6 I would have said probably 32mm CV carbs, but I see Type 53 mentioned here too.

The OP was about the R60/6. The R60/5 and /6 came with slide carbs, probably the Type 53 mentioned. The R75/5 and /6 bikes came with CV carbs. The R90/6 had the CVs while the R90S had the Dellortos.
 
I have a R60/7, which has the same type 53 version as the /6, and I want to reintegrate the importance of cleaning the choke/enricher. The end of the choke ÔÇ£pistonÔÇØ (where the cable attaches to) has a rubber pad. The pad can disintegrate with time and wreak havoc. The little bits of rubber can plug passages and make things run lean. Alternatively, the absence of the rubber pad can keep the choke from sealing and make the carb run rich. I suspect that carb cleaner is not kind to the rubber and can contribute to its decline. I recommend you take the choke assembly out and make sure it is in good order. You need to do this to clean the choke passages anyway. After I cleaned my carbs passages with fine wire and replaced the choke piston end it was much easier to sync the carbs.
 
I have a R60/7, which has the same type 53 version as the /6, and I want to reintegrate the importance of cleaning the choke/enricher. The end of the choke “piston” (where the cable attaches to) has a rubber pad. The pad can disintegrate with time and wreak havoc. The little bits of rubber can plug passages and make things run lean. Alternatively, the absence of the rubber pad can keep the choke from sealing and make the carb run rich. I suspect that carb cleaner is not kind to the rubber and can contribute to its decline. I recommend you take the choke assembly out and make sure it is in good order. You need to do this to clean the choke passages anyway. After I cleaned my carbs passages with fine wire and replaced the choke piston end it was much easier to sync the carbs.


HOT DAM!

I cannot TELL you how frustrated I have been about my rich-running... and have finally convinced myself that it just HAS to be the chokes.... I even pulled them out today, looked at the bottom, looked at my Bing Book (which btw does NOT show a rubber piece) and resolved to call Bing tomorrow....about whether there should be a rubber bottom.... yeehaw! I have pulled the carbs so many times, blown out the air passages, blah blah blah... and this is the first time I have read/seen this.

I ran with a buddy's 75/5 a coupla weeks ago up in Tennessee: we filled at the same time, and I took 1 GALLON more when we re-filled: spewing black smoke upon acceleration.....

Thank you:bow
Thank you:bow
THANK YOU :bow

HALLELLUJAH! My answer! :clap
 
One other thing to check for rich running is the accelerator piston/plunger. This is the brass barrel like thing in the accelerator pump. It is held up by a spring and pushed down on by the needle. It, in conjunction with the needle, controls fuel flow above idle. There is a little white plastic disk about 1/8" (3mm) in diameter inside the plunger. You can see it in the BMW shop manual and the Bing picture of the type 53 (part 38 in their drawing. They call it a ÔÇ£reedÔÇØ. A PO had lost or intentionally removed it from the plungers. This makes the bike run rich from above idle until about three fourths throttle. With it out the bike started like a dream but would bog badly above idle once warmed up. It took me four months to determine it was missing and less than two dollars from Bing to replace.
 
I called Bing today, and found that the little rubber thing is not available separately from the "piston" (#48 in Bing's Type 53 pdf), but they are dropping two pistons in the mail for me.... The pistons are $8+ each, plus shipping... those are $$ little bitsarubbers!!

Thanks again for the tip.

:clap

and btw, yes, I had gone through the accelerator "pump" which was all as it should be, per the parts diagram... everything else checked out perfectly.. so this rubber piece at the bottom of the choke plunger was the last piece ( knock on wood....)
 
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I have a R60/7, which has the same type 53 version as the /6, and I want to reintegrate the importance of cleaning the choke/enricher. The end of the choke ÔÇ£pistonÔÇØ (where the cable attaches to) has a rubber pad. The pad can disintegrate with time and wreak havoc. The little bits of rubber can plug passages and make things run lean. Alternatively, the absence of the rubber pad can keep the choke from sealing and make the carb run rich. I suspect that carb cleaner is not kind to the rubber and can contribute to its decline. I recommend you take the choke assembly out and make sure it is in good order. You need to do this to clean the choke passages anyway. After I cleaned my carbs passages with fine wire and replaced the choke piston end it was much easier to sync the carbs.


This is what I had (notice lack of rubber, notice large orifice through which fuel can flow.....)
680017473_B9WBF-M.jpg



And this is the little rubber pad that should have been there, and "the absenceof the rubber pad can keep the choke from sealing and make the carb run rich."
680017430_TM5xj-M.jpg


:D

Needless to say, there is a "noticeable" difference in the mixture... no more black smoke spewing forth when revved, and it now IDLES correctly....:bow thank you !

:D
 
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