The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: weasel01 on July 30, 2009, 11:23:04 AM
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I have really been enjoying my resurrected r65 but a couple nights ago at highway speed I noticed some roughness that wasnt there before.
When I got home I checked the diaphragms as I've seen this condition mentioned several times here.
Sure enough the left side has some damage.
So I ordered a rebuild kit from Bob's BMW and hopefully I will be rebuilding them this weekend.
Also order new cables (most expsive single purchase so far).
Any words of advice from you experienced ones?
I'm using bing diaphragms.
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Well, it's too late now but next time order stuff like this from Moto-Bins! On the cables just make sure you route the new ones back exactly is your old ones... Have fun with the splitter! :P
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Oh, come on, the cable splitter is not that much of a big deal !!!!
The first couple of times I removed the cables from the bike, I taped a length of string onto the rest of the cable/wiring harness, just to be sure to get it right upon installation .
Remove the three cable assembly from the bike .
Thread the cable adjuster in all the way where the single cable goes into the splitter .
Next unscrew the threaded cap on the splitter, push the single cable in all the way you can, push down on the piece of plastic that the cable sits in, the single cable should be pushed out of it's detent to disengage it from the plastic 'plug', then move the single cable to the side through the slot in the plug and push it down out of the way, so it can't get hung up on the plug , then the plastic plug with the two cables that go to the carbs will come out .
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Thanks guys, I'm still mad a motobins for shorting me 2 gaskets on my timing chain kit.
Bob's had everything in stock ...ordered monday afternoon , just arrived via fedex.
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I am also thinking of rebuilding my Bings (32 mm flat tops) and put it back on the bike. Currently running two Mikunis VM32 Round Slide.
Anybody have any experience with Bing's Carb Kit? Is it more expensive than Motobins, Max's or any other dealer?
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My bike has the 32mm bing carbs and the rebuild kit was $74.00
for both carbs a buck or 2 more than just the diaphragms.
I received my cables today and hope the get my carb kit tomorrow
If I get it early enough I will try to post a picture.
The cables came with all new adjuster to screw into the carbs.
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If not already in your shop, go ahead and build El Cheapo Grande manometer so you'll have it ready when it's time to synchronize the carbs after rebuild.
Visit Snowbum's carb rebuild and synch'ing articles for a look into the future. helpful. Call us if you get lost [smiley=thumbsup.gif]
http://bmwmotorcycletech.info/
Monte
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Cool, got my rebuild kit today.
Looks good and complete.
Will be tearing it down tonight!!
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Cool, got my rebuild kit today... Will be tearing it down tonight!!
Take lots of digital images to aid in remembering where that little widget came from. Sketches. Sequence notes. Perhaps consider doing one Bing at a time so you'll always have a complete reference. You may find that the job will go quicker due to less mental stress... Ah jeez. Where did I get that o-ring from?
You'll have fun, Ampy. Monte
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OK left carb cleaned / new orings / gaskets /diaphragm.
Very straight forward.
All but 1 oring was mush... very deteriorated.
The oring on the choke lever looked good as new ...changed it anyway.
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got em both overhauled.
Mounted them and the ol' girl fired right up!!
Went out for an operating temperature building ride came back and went thru the carb sync procedure.
Balanced em' on the homemade manometer.
Went for another ride and this is what I notice.
The throttle resistance is 60% less no longer does it feel like it's divided into ranges now it's smooth and equal resistance top to bottom.
My acceleration is much more rapid and effortless ...before there was alot more "work" involved in taking off from a dead stop.
I was really dreading the cables but they were by far the easiest point of this weekends surgury.
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Ah, the sweet satisfaction of a job well done - at considerable savings over the dealer! ;D That is, if you could even talk your local dealer into even letting it into the service bay... :-/
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You should also see a definite increase in fuel mileage after the carb overhauls. Post Bing rehabs, my '81 now pulls smoothly up to and beyond 80 mph. Would be no problem going faster but I began to scare myself and whoa'd up.. :P Monte
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I have been tweaking on these carbs here and there and have them almost perfect except for the slightest hesitation right off of idle?
The idle is perfect and the rest of the throttle range is smooth as silk?
What is the trick to eliminate that slight hesitation?
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Maybe go a bit richer (equally on both sides) on the idle mixture screws. What you are seeing is a flat spot between where the idle jets are in control and the mains take over. Sometimes a bit richer idle adjustment will get you over this...
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Thanks Justin I will try that.
The only thing I noticed inside the carbs that caught my eye was one of the needles had a small nick in the side of it the other was shiney and new looking?
Could this be contributing to my issue?
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I suppose that any damage to the "needle" part of the screw could cause difficulties of some kind. Another thing, if the idle mixture doesn't help, might be to raise the slide needles a notch. I have had a clogged up "intermediate jet" but this caused a whole lot more than a brief flat spot. But, you might want to make sure all of the little bitty holes in the intermediate jets are clear and also that the O-ring on the jet didn't get sliced when putting it back together...
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Big box stores like Lowes, Home Depot, Menards or even Ace Hardware carry little plastic tubs of "Plumber's Grease". It looks and feels like our favorite dielectric grease but I dunno what it's composed of.
Anyway, this stuff -applied in very small portions- goes a long way in preventing tearing, galling, rolling, etc of rubber O-rings and other similar bits.
I used the stuff during the Bing overhaul adventures with Blackie to insure a no-damage reassembly.
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I just use silicone grease. I hate anything even remotely related to plumbing... [smiley=puke2.gif]
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I'm pretty sure it's an adjustment issue as the carbs are much touchier than before (probably because they are working correctly now)
I'm gonna try the richer setting Justin suggested.
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I just use silicone grease. I hate anything even remotely related to plumbing... [smiley=puke2.gif]
Gotta be a really good story in there somewhere ;)
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I fiddled with the mix screw a bit and improved the just off idle response
but at the cost of the super smooth engine sound.
Did a bit of research and found several references to the transition from idle to "go" rpm increase was more affected by cable balance?
I'll try that next..
Read a cool debate on another forum about the sync method of just off idle (say 1300 to1500rpm) vs. 3k to 4k rpm method?
Snow bum says above 1500 is a waste of time (with bing cv)as the adjustment is less dramatic than just above idle ....logarithmic response is guess...
thoughts?
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Although I did not need to change out throttle cables during the overhaul of my 32mm's, I did work quite diligently getting the cables just so.
I found that the amount of slack in each cable must be perfectly equal or the engine may stumble just off idle as you pull away from a stop. Sound familiar?
Note that the air mixture screw position on the Bing makes a rather large difference in carb operation. Very small position changes create even larger operational changes. There's usually no more than one-eight of a turn between the stock 3/4 out and an ideal run position. They are touchy little rascals.
Also, just moving off idle, the Bing's fuel metering begins transferring to the needle and needle jet system. Your nicked needle could be hanging up in the needle jet but not likely if you smoothed it off. The main jets begin to meter fuel from perhaps 80% throttle up to WFO.
Revisit your cable adjustments; primarily at the length adjust screw on top of the carbs. Bet that's where you'll lose the off idle weirdness.
[smiley=2cents.gif] Monte
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Ok ...got it lined out.
Went for a nice long ride on my way home today pulled up to my garage I prepped the fan manometer and tools this morning so it was all ready to go.
I think I'm getting some "new cables settling in" phenomenon.
Went back thru the whole proceedure and it feels great again!
We will see tomorrow but it felt right tonight.
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...could be those new chickens messin' with your ride. ;D
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...could be those new chickens messin' with your ride. ;D
I tell ya' what if I catchem' ...it's straight to the fryin' pan!!!
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drgnfli,
I've often thought that eventually when my bings need major service, I'd swap in Mikunis for the sake of newer engineering, cheaper more available parts, and less worry about that diaphram.
Do you want to switch back for the sake of maintaining originality? How did the Mikunis perform?
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Dang it ...it might be those chickens after all...
I had it dialed in perfetly last night ...went for a long cool down ride and it wass silky smooth.
This morning it was super hard to start and my hesitation off idle is back?
This has proven to be the hardest step to get right so far....
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Hard to start and off-idle hesitation may be two different chickens.
The Bing float bowls have a separate fuel reservoir for the enrichment system... hereafter known as the choke.
There is a tiny brass plug in the bottom of the choke reservoir that connects with the main bowl. It must be clear so that fuel can move between the two chambers and remain at the same levels. There is a small brass tube from the carb body that extends into the choke's fuel chamber.
Sometimes fuel deposits clog this tiny orifice which leads to hard starting. Usually, it's just one cylinder that's not hitting until the engine warms up a bit.
Perhaps return to "square one" with the idle jet screw at 3/4 out. See if starting is easier.
I would get discouraged and mildly p*##ed at my Bings but if you can stand the strain, you'll get it sorta out. Have you confirmed that the diaphragms are properly seated with the little rubber tab in its tab hole?
Monte
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Yes diaphrams are properly positioned...I just cleaned the sh!t out of both carbs but you know ....now that you mentioned it this morning I did notice (when it finally started) the right cylinder fired before the left?
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...now that you mentioned it this morning I did notice (when it finally started) the right cylinder fired before the left?
Must be something else, Ampy. It was my left cylinder. ;) ;D
Monte
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bjamesw,
Bought the bike with the Mikunis already installed by PO. He gave me the Bings that was previously on the bike. He said his foot got soaked with fuel one day and he just decided to replaced the carbs.
Mikunis are alright, had to play a lot with air and idle screw and different jets to get optimum performance. It's great right now but still wondering if "I got it right " now. I haven't balance the carbs
yet. I need to buy or constuct those cheap manometer and I think
drill and tap some hole in the Mikunis where the balance tube will go in. Didn't do it yet because I have no idea where to drill and too afraid to screw it up. I guess to find out the best setting/adjustment on the carb is to put in on Dyno but I again I dont know if it is worth it and I dont want to spent any more hard earned dollars. So right now, it's my ear and test ride that determine if the adjustment/setting are optimal.
Reason for why I want to put back the Bings is, I dont know how the the bike run with original carb. I am wondering may be it's better
than the Mikunis. I don't know, I do not have anything to compare right now. Just wondering how the bike will behave will original Bings.
Drgnfli
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Yep...I have some problem here I'm not seeing?
I get a perfect balance on the manometer ...idle is perfctly smooth and riding rpm is smooth and even take offs are smooth unless it idles for more than 30 seconds (like at a light) then it stumbles when I twist the grip...
I have to blip the throttle to get it to go ...or hold the rpms slightly above idle.
I found my hard to start remedy to be a readjust on the choke cable...it now starts immediatly idles great but studders off the line?
I noticed the right carb doesnt have as much rpm change as the left but thats the only difference?
I'm going to build a plug shorting setup today so I can hear each side independantly....
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If the rubber sleeve connecting the carbs to the head is too long there will be a gap between the carb and inlet stub. This can fill up with condensed fuel and cause a rich stumble off idle that would probably clear after being ridden and maybe happen again after a period of low speed /idle .
Does this fit your symptoms ?
I remember reading about one guy who machined brass spacer rings to fill the gap. I just shortened the rubber sleeves a little and it seemed to help.
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Thanks Barry, I installed new BMW inlet hoses as part of my overhaul.
The carbs seem to sit perfectly? No gap.
I made shorting pins for my spark plugs and the cylinders sound the same?
I rechecked my timing (just replaced timing chain recently) and both settings are perfect too?
I pulled the carbs again just to check for any unseen blockages and everything looks just right?
I'm really baffled...it does "OK" for about 15 minutes of riding (this already hot after manometer adjustment) then slips back to the studder thing again?
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When I replaced my carb cables I noticed that one of the weak points was where the ferrule end connects to the carb body. The ferrule is rigidly held at the body, and the cables tend to flex right at the ferrules and the cable within has to make a sharp bend. Good spot for some strain relief. For each of the throttle and choke cables (all four) I cut a (approx) one inch, a two inch, and a three inch section of black electrical shrink tubing. Shortest (inch) one first, covering the ferrule all but the male section that mates with the carb body. Heat it tight. Then do the two and three inch sections likewise. Even better, if you have it, is adhesive lined shrink tubing. When I don't have the adhesive lined stuff, I wrap a single thickness of Scotch double-sided clear adhesive tape over whatever I'm putting shrink tubing over. Waterproofs and keeps everything ultra tight.
Worked out beautifully! I posted a pic here somewheres a few years back.
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Hey Bjamesw,That's a cool suggestion...however I have visions of a heat gun , gasoline and me.
That could be a bad combination!!
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ok here is my new question....at what rpm is the charge light supposed to go out?
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I would say around 14-1500 rpm, it all depends on the state of charge of the battery .
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Well....I'm having a bad time with this.
I have adjusted readjusted re re adjusted re re re adjusted re re re re re adjusted and get the same result..
I pulled the spark plugs and they look fine.
I've started at 1/2 and at 3/4 turn on the mix and end up at the same sweet spot ...I've set the cable mix at 1300rpm 1500rpm and 3000rpm
I've set the idle as low as 1100rpm and as high as 1250
I've gone as lean as possible and as rich as possible I've balanced and rebalanced between each step.
The end result is perfectly smooth idle perfectly smooth mid and top range even smooth take off if it's within a few seconds.
What is escaping me is if I'm idling for more than 10 seconds there is a studder when I roll the throttle on (there is a "too rich" crakle that happens only then)
Most of the time it's minor but more than a couple times it has stalled at a traffic light which is not cool at all.
My best result is a higher idle rpm but I can still "sense" the studder spot as soon as the throttle is rolled on.
It's very even smooth and pleasant except for this .......
any suggestions appreciated! ...except anything chicken related!!!
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In trying to visualize your off-idle stutter... Engine is at operating temperature and everything is fine except for the engine stutter as you're attempting to pull away from a stop sign, etc.
As I've followed most every line you've written about your R65, it sounds as if you have done everything per specification. But your concern continues...
When you worked on the Bings, did you remove/replace the butterfly valves in the carbs? There are older posts on different sites that discuss the importance of centering each brass plate within the bore of the carb's throat. If a throttle plate drags, it could create symptoms as you have described. If one butterfly is dragging -even a tiny bit- that Bing will be delayed in beginning the fuel delivery and create a stutter until it unsticks itself. Then, all's well until the next stop. At operating temps, heat expansion could be affecting the brass butterfly. Yes, I may be reaching here...
Pulling the carbs and shining a bright light into the throat should reveal an equidistant gap around the valve's circumference and the throat bore. If the butterfly drags, loosen the anchor screws a bit and re-center the valve.
This may be a stretch but I'm about stumped. Anybody? Monte
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The only thing that I can think of is perhaps the auto advance springs in the bean can might be sticking momentarily causing the stutter. I'm reaching too, but just give 'em a quick shot of WD40 as a temporary fix. It won't hurt anything and may isolate the cause.
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Yet another 'shot in the dark', how do the pressed in caps on the upper cover of the carbs look ?
They come loose on rare occasions .
Was this hesitation present brfore you worked on the carbs ?
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When you worked on the Bings, did you remove/replace the butterfly valves in the carbs?
Yes, I did remove both of them and had a real bear of a time getting them back in place.
I just looked at them again when I had it apart for thwe 2nd time last sunday and they looked equally seated?
Like I've said before give me a soldering iron and watch me go... stick a wrench in my hand and watch me fail....
That is a reasonable suggestion so I will pull them back off a look again with a light this time.
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Bengt and Bob, Thank you for the suggestions but this all happened immediatly following the carb rebuild?
And except for the tiny tear that aprreared in the diaphragm everything was fine as wine?
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As I understand it, the butterfly valves can be fitted the wrong way round as the edges are not square. The resting position is not 90 Deg so the edges are slightly angled to fit precisely in the bore.
Is this a possibility ?
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As I understand it, the butterfly valves can be fitted the wrong way round as the edges are not square. The resting position is not 90 Deg so the edges are slightly angled to fit precisely in the bore.
Is this a possibility ?
I noticed that and since I rebuilt only one at a time I had the other to copy from.
Judging by how small the mix hole is and how much effect it has on the operation of the carb it's real possible the butterfly could be the culprit.
cant wait to get home to try it!
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But no pressure. Right, Ampy? Good luck, buddy.
Steady breathing, calm, ahmmmm...
Monte
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I got home managed to pull my carbs off and pull all the idle set screw out so each throttle would bottom out all the way for an accurate measurement .
I have shone a light down the backside of each carb and DO see a difference.
Measuring as closely as possible with a digital caliper I find a difference of .039mm between the carbs.
This doesn't seem like a lot but as stated before tiny differences make a major difference in carbs.
It at least gives me hope that there is a previousely unnoticed difference.
I took pictures but they are not clear enough to see.
I didnt get to do any actual changes tonight because of a prior engagement but will do it first thing in the morning!
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Thanks to all who have suggest possible solutions!!
The problem SEEMS to be gone completely and entirely!
It was the throttle plate alignment...I took both carbs off and did the flashlight test and a small amount of light was passing thru each butterfly but in different amounts.
When I pulled the throttle arm light came thru the top side first.
I loosened the 2 screws on each gave a quick jiggle on the thottle arm holding the carb upside down and it fell into a perfect seat so NO LIGHT AT ALL passed and as I pulled on the throttle arm the light came thru equally all the way around.
Reinstalled the carbs went for a warm up ride and instantly noticed an improvement.
Got back from a 10 miler already had my manometer, fan and tools ready to rock pulled in the garage went thru the proceedure (I've gotten really good at it lately) went out for another test ride and IT WAS PERFECT!!!!!! I can sit at a stop light for minutes without touching the throttle then roll it on smooth as you please!!!
Monte had the winning suggestion and for that I am truly thankful!!
And to show my sincere thanks I have decided to NAME ONE OF MY CHICKENS AFTER MONTE!!!
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You said you loosened the screws on the throttle butterfly plates, after tightening the screws, they need to be 'peened over' on the back side to prevent them from vibrating loose .
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You said you loosened the screws on the throttle butterfly plates, after tightening the screws, they need to be 'peened over' on the back side to prevent them from vibrating loose .
Bob, I opted for the blue loctite per snowbums site....hopefully that will work.
I also lightly crimped the threads on the backside sticking out.
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As long as you did something to the screws, as I don't think they would stay in place without Locktite, or peening .
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...And to show my sincere thanks I have decided to NAME ONE OF MY CHICKENS AFTER MONTE!!!
[smiley=ROTFLMAO.gif]
Truthfully, Ampy, your last line caught me flat-footed. Nearly fell outta the chair laughing so hard. Had to show my wife... she didn't get it. Wonder why?
I'm honored. Post a pic of my namesake. ;D Ain't we havin' fun here at the R65 asylum? Monte
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You named one of your free range laying hens after Monte? That is too cool! [smiley=ROTFLMAO.gif]
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That thought did cross my mind. Perhaps Monica? ;)
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details, details
The official name is "Monte the Voodoo hen" I took pictures this morning and will post them tonight
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Could this be the newest avatar for Monte? Stay tuned!