Bing 53 carbs

I am new to the BMW MOA, and new to BMW bikes.

I just purchased a 1974 R60/6, with 51k, but have had motorcycles, off and on, since 1967.

I am restoring a 1980 Velorex 562 sidecar, and the R60 seems like a perfect candidate for this.

The previous owner of the R60 had gone through a number of mechanical systems, as well as some cosmetic improvements, to make this a reliable bike. It still has room for improvement, but overall, a nice classic machine. It started well, ran out nice, new tires and battery, so I brought it home.

After all the paperwork, tags, insurance, I took my first ever ride of about 40 miles yesterday. Upon arriving home, the left carb began leaking out the bowl overflow, so I removed the carb to clean, check the float needle/seat, and float level. As my Clymer service manual has not yet arrived, I pulled a diagram off a site for info.

I have two questions: the idle jet had the rubber o-ring wrapped around the threads. Where is this o-ring placed? The diagram shows this appears to go in first, followed by the idle jet; however, the idle jet does have a groove under the slotted head - not sure of correct placement.

Secondly, I cannot find what the correct float level should be, or where it's measured from.

The needle/ seat appeared fine, but the carbs definitely needed cleaned, and the bike still had old gas in it from early spring. I've never worked on Bing carbs, but they seem straight forward - just don't have the specs yet.

Any comments/suggestions appreciated! Thanks. Richard

DS74BMW said:

I am new to the BMW MOA, and new to BMW bikes.

I just purchased a 1974 R60/6, with 51k, but have had motorcycles, off and on, since 1967.

I am restoring a 1980 Velorex 562 sidecar, and the R60 seems like a perfect candidate for this.

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Although a of folks run sidecars on 1969 ( /5) and newer, BMW strongly recommended against it due to the lightened frame. The sidecar is basically doing everything it can to leave the bike. You can do it, but you should look into (at least) a strong subframe support (Tarzan in Pennsylvania can do this) and spoked wheels. The load can crack a cast wheel like a snowflake or Lesters (you might already have this).

DS74BMW said:

...After all the paperwork, tags, insurance, I took my first ever ride of about 40 miles yesterday. Upon arriving home, the left carb began leaking out the bowl overflow, so I removed the carb to clean, check the float needle/seat, and float level. As my Clymer service manual has not yet arrived, I pulled a diagram off a site for info.

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Mine did the same thing, even after I'd rebuilt them. I found it was leaking from the fiber wash seal at the bottom of the bowl on the aluminum drain port nut. I tefloned it and all it has stopped (not sure how long that'll last with gasoline, but 3 months so far and no drips). Yours may not have this.

DS74BMW said:

I have two questions: the idle jet had the rubber o-ring wrapped around the threads. Where is this o-ring placed? The diagram shows this appears to go in first, followed by the idle jet; however, the idle jet does have a groove under the slotted head - not sure of correct placement.

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The o-ring indeed goes into said groove.

DS74BMW said:

Secondly, I cannot find what the correct float level should be, or where it's measured from.

The needle/ seat appeared fine, but the carbs definitely needed cleaned, and the bike still had old gas in it from early spring. I've never worked on Bing carbs, but they seem straight forward - just don't have the specs yet.

Any comments/suggestions appreciated! Thanks. Richard

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Best $10 you'll ever spend: http://www.bingcarburetor.com/manual.html

Hope this helps.

Thankyou.
I do plan to fab/buy a sub-frame. My bike does have spoked wheels.

My Bings do not have the bowl screw - I think the fuel was from the overflow. My Bings have the number 1/26/123 stamped on the body

I saw that manual on the net, and plan to get one, but I could use a float ht dimension now, as I have the carbs off at present. I'm sure the ordered Clymer manual has this info, too, but would like to button it up and ride

I appreciate the quick reply - again, thankyou.

DS74BMW said:

but I could use a float ht dimension now, as I have the carbs off at present.

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I've never worked on the Type 53 carbs, but a starting point for float height is to turn the petcock off and drop the float bowl. Then with your finger holding up the float to close off the valve, turn on the petcock. Slowly lower the float until gas just starts to flow. See where the horizontal mold line on the floats is in relation to the bottom flange of the carb body. They should be roughly parallel. Shut off the petcock and make the adjustments. There should be a small tang that presses up on the bottom of the needle valve. Bending this tang will change when the needle valve engages the seat. Don't be hamfisted in working in this area. Too much pressure and you can damage things or break off a mounting flange for the float pin.

There's another measurement that I'm aware of but it applies more to the CV carbs. One measures the depth of the gas in the float bowl after it's filled and then closing the petcock. On those carbs, the depth of the fuel measured in the middle of the bowl is around 22-24mm...varies a little bit by carb size. My guess is that it's something on this order for your carbs.

The depth of the fuel is a more precise way of getting the proper adjustment. The parallel test is OK if everything is perfect...the float was manufactured properly and it has the correct bouyancy. Floats age over time and begin to sink.

Thanks, Kurt - good info. I'll check the fuel level on the carb that wasn't leaking, although that doesn't mean it's correct, either, but a place to start.

I agree, ham-fisted and carbs are not good bedfellows!

The carbs are now thoroughly cleaned, adjusted, and sync'd. I think, after seeing what was in these, that dirt probably interfered with the needle/seat on the left side. The bike is more responsive, starts and idles very well. I had almost forgotten what a pleasure it is working on a twin, let alone one that is superbly engineered.

Any recommendations for a good on-line source for BMW parts? There are no convenient dealers in my area. I found today, during my work, that the "ring/pinion" type throttle assembly does need freshened up - wear on the "teeth" inhibits smooth operation. I certainly like the design! I really believe this R60 was a good choice for this, and my wife really likes it.

BTW, a couple pics of my sidecar before I started restoration; the primary reason for this project was so that my wife and I could take our dog with us:







under restoration:

Sounds like you got the carbs problems sorted out. Good deal.

For parts needed from a dealer, I generally reference either maxbmw.com (online catelog) or realoem.com to
get the specific part numbers, then check maxbmw.com, chicagobmwmotorcycle.com and sometimes Bob's for pricing.
Chicagobmw has pretty good prices, but you probably need to call them and ask for the 20% discount--and delivery has
been slow in my experience. 2-3 weeks, so you'll want to make sure it's a good deal cheaper.

Other vendors I've used:
Rocky Pointe Cycle
Ted Porter's Beemer shop
EU BMW (although not that often)
Motorrad Electrik (highly recommended, although I've never received a call back-- I think you need to be persistent and hope to reach Rick directly).

Used parts from
ibmwr.org (I keep a list of straight shooters I've dealt with and reach out to them first)
craigslist.com (for local stuff)
MOA Flea Market
Hucky

Reference Sites:
www.bmwmotorcycletech.info (Snowbum's legendary--hard to read, but amazing advice--site)
http://largiader.com/ (Anton's site--straight shooting and accurate advice)
http://www.bmbikes.co.uk/information.htm (specification site, most models and mostly accurate)
http://www.beemergarage.com/ (Self proclaimed largest number of BMW articles and photos on the net )
http://w6rec.com/duane/bmw/index.htm (Duane Ausherman's site, good advice here)

That should keep you occupied for a while. Also, the airheads.org group has good stuff and of course Oak's tech index.

Nice looking sidecar. Please keep us posted on the progress.

DS74BMW said:

Any recommendations for a good on-line source for BMW parts? There are no convenient dealers in my area.

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I've had good luck and great service from Ted Porter at http://www.beemershop.com. He's located in NorCal.

Vech in Mississippi has mostly /2 parts but has expanded his inventory to include later bikes too. http://www.benchmarkworks.com.

I've never used Hucky before, but people have said good things about him. http://www.bmwhucky.com.

Of course, all things electrical can be had at Motorrad Elektrik...http://www.motoelekt.com.

That is a great looking sidecar and fabulous garage. Are you a machinist? It looks like you have some of the equipment.

I haven't worked on the type 53 carbs but you will get good info from others. The Bing book is money well spent. Some of the information and exploded drawings are available on their website.

Thanks, guys! I definitely need to start a "Source Book" - a lot of possibilities here! I will start checking these.

Yes, I am a toolmaker [laid off at present, however]. The small bench mill is suitable for only very small work, and is not fully tooled up yet.

I appreciate the willingness to help a newcomer! Thankyou all! I am looking forward to getting into this bike - I enjoy wrenching almost as much as riding.

Now that the carbs are clean, I will plumb in a couple of small in-line filters soon.

DS74BMW said:

...I enjoy wrenching almost as much as riding.

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You'll fit in well as an airhead!

DS74BMW said:

Now that the carbs are clean, I will plumb in a couple of small in-line filters soon.

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For whatever its worth, I'd pull the petcocks off first, replace the long screens and the tiny interior ones. Each petcok should have two. They are much finer mesh than external filters. I've removed my external filters after talking with Tom Cutter (rubber chicken racing garage in NJ) because they only effectively slow down fuel delivery. In the end, its just gravity fed and I'm not racing, so it could probably go either way. I just got tired of replacing them since they were a rougher grain filter than the fuel that had already been filtered.

AnnapolisAirhead said:

I just got tired of replacing them since they were a rougher grain filter than the fuel that had already been filtered.

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Good point. Thanks

AnnapolisAirhead said:

For whatever its worth, I'd pull the petcocks off first, replace the long screens and the tiny interior ones. Each petcok should have two. They are much finer mesh than external filters. I've removed my external filters after talking with Tom Cutter (rubber chicken racing garage in NJ) because they only effectively slow down fuel delivery. In the end, its just gravity fed and I'm not racing, so it could probably go either way. I just got tired of replacing them since they were a rougher grain filter than the fuel that had already been filtered.

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Interesting,
You still see a lot of external filters on Airheads. If the fuel is already filtered, then why the external filters? Are some of the earlier petcocks not filtered? I've often wondered if I'm getting the maximum fuel flow, but I know my petcocks need some attention. I use a tank bag too which might affect venting. Maybe I'll just service the petcocks and dump the external filters. BTW DS74, could you come over and clean and organize my shop? Later,
Geoff

I like the external filters because I can see if fuel flowing. Even if I only have one petcock on, I get plenty of fuel. So the external filters are not restricting fuel flow. On the other hand, I have fairly low expectations for their filtering capability.

It is a bad idea, but many airheads have had their filters removed.

Be sure to invest in some "Doggles" for fido, as well as a decent restraint harness (don't attach a lead to a plain neck collar to keep him in the sidecar). It looks like the introduction to the sidecar has already begun - that is very good !

sumran said:

I like the external filters because I can see if fuel flowing. Even if I only have one petcock on, I get plenty of fuel. So the external filters are not restricting fuel flow. On the other hand, I have fairly low expectations for their filtering capability.

It is a bad idea, but many airheads have had their filters removed.

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My thinking Randy, is that they didn't come from the factory with them and I am pretty vigilant about pulling the petcocks and cleaning them including the screens to check for sludge--heck, I probably replace them and rebuild the carbs a lot more than most people. I figure, one day I'll get the hang of it and I like clean and shiny things the ultrasonic cleaner does to parts.

I ride with the starboard petcock open and don't have any flow issues either. It may be dark in those fuel lines....but I have a sneaking suspicion that there is fuel flowing.

AnnapolisAirhead said:

My thinking Randy, is that they didn't come from the factory with them and I am pretty vigilant about pulling the petcocks and cleaning them including the screens to check for sludge--heck, I probably replace them and rebuild the carbs a lot more than most people. I figure, one day I'll get the hang of it and I like clean and shiny things the ultrasonic cleaner does to parts.

I ride with the starboard petcock open and don't have any flow issues either. It may be dark in those fuel lines....but I have a sneaking suspicion that there is fuel flowing.

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Ah, but what about when it is not running or cutting out? A quick glance at the filters is easier than dropping the float bowl. Just my preference, not an important issue by any means.

Geoff said:

Interesting,
You still see a lot of external filters on Airheads. If the fuel is already filtered, then why the external filters? Are some of the earlier petcocks not filtered? I've often wondered if I'm getting the maximum fuel flow, but I know my petcocks need some attention. I use a tank bag too which might affect venting. Maybe I'll just service the petcocks and dump the external filters. BTW DS74, could you come over and clean and organize my shop? Later,
Geoff

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I have a Pingel filter on my other bike; it uses a scintered brass filter media, and used mainly to catch contaminants from fuel line erosion. I don't recall the flow rate it's capable of [rate on Pingel's site], but I've never had a starvation issue feeding four 36mm Keihins. I replace the fuel line every spring, as I have found rubber particles in the media.

Geoff, I think you are a little too far away for me to help with your garage! I can send you some pics - I did the repairs/painting, and my wife decorated a good portion of it - she does have good tastes - of all the bikes we looked at for the sidecar project, when seeing the R60 [she had never seen a Boxer Twin], she said first, "What are those things sticking out the sides?", immediately followed with, "I love this bike - let's buy it!"

boxermaf said:

Be sure to invest in some "Doggles" for fido, as well as a decent restraint harness (don't attach a lead to a plain neck collar to keep him in the sidecar). It looks like the introduction to the sidecar has already begun - that is very good !

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My wife already purchased Doggles [in red to match the dog's harness - leave it to my wife to make sure colors are coordinated!], and has researched various restraint systems. I agree, a collar only can potentially injure the dog.