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Old 06-19-2012, 03:17 PM   #16
rusty44
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Quote:
Originally Posted by ozmoses View Post
Matt- at MAX speak w/ Rusty in the parts dept.

+++++++1 Rusty is a GREAT GUY!!!!!!!
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Old 07-03-2012, 08:19 AM   #17
mattsz OP
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Got my parts at MAX - pretty flashy joint. Lots of salesmen surrounded by fancy bikes waiting to pounce on prospective customers... of which I wasn't. Took over an hour to buy some filters, gaskets, crush washers and a few quarts of oil. Wasn't sure what else to get, or whether I needed to get BMW oil, but I was there...

Can anyone describe "pinging" to me? Yesterday, my bike started making a rapid, somewhat random, not-too-loud "tinking" noise when under load, i.e. climbing a long steep hill at about 3500 rpm. Lower gears and higher rpms helped, but I have to keep the bike moving, for goodness sake! I might have called it a "ticking", but it has a vaguely metallic tone and it isn't like the ticking of what I think is the valve lifters - and it only happens when I load the engine. I have high-test gas in the tank, but no other additives.

Is this the dreaded pinging that these bikes are "known for"? Will it cause damage? What should I do about it?
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Old 07-03-2012, 08:58 AM   #18
Bill Harris
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Use premium grade gas and check the timing. Otherwise, install low-test base gaskets to lower the compression ratio.
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Old 07-03-2012, 09:12 AM   #19
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Quote:
Originally Posted by Bill Harris View Post
Use premium grade gas and check the timing. Otherwise, install low-test base gaskets to lower the compression ratio.

Thanks, Bill. I take it from your repIy that this is pinging that I'm experiencing. What kind of damage will it cause, and how quickly? If it doesn't happen often, is it safe to ignore it?

I use premium grade gas, and checked the timing a few weeks ago. Should the timing be set a certain way to avoid the problem?
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Old 07-03-2012, 10:35 AM   #20
Bill Harris
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Yep, the sound is a lot like gravel rattling around in a tin can. No immediate harm but it ain't good-- back off the throttle a bit and/or keep the RPMs up. Double-check the timing-- it shouldn't be past the "Z" (or "F") mark.

The R60-series has a cam profile that gives a high effective compression ratio and(at least the /5) has 9.6:1 physical compression ratio and was designed to run on the bestest tetraethyl lead Premium gasoline. I'm thinking the /6 was the same way.

In the early '80's when good leaded Premium became scarce I had this same serious problem and my solution, at the time, was to install a set of "Low Test Base Gaskets", a BMW part that lowers the CR from 9.6 to 8.6 (-ish) and allows the engine to run happily on Regular. You take a slight hit in performance and gas mileage, but not a devastating one. Last year I did a top end on my R60/5 and did (my one last) performance mod on it: went back to the normal, high-compression base gaskets and modded the heads for dual plugs. Bike is a little zippier and I guess one could consider the lower plugs a Farkle.

Your call...
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Old 07-03-2012, 12:37 PM   #21
mattsz OP
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Quote:
Originally Posted by Bill Harris View Post
Yep, the sound is a lot like gravel rattling around in a tin can. No immediate harm but it ain't good-- back off the throttle a bit and/or keep the RPMs up. Double-check the timing-- it shouldn't be past the "Z" (or "F") mark.
What I hear sounds more like tiny pebbles in a can, but I imagine that it's the same thing! Just so I can get my head around preventing the problem - does the timing want to be advanced, or retarded, or right on the money?

Quote:
Originally Posted by Bill Harris View Post
In the early '80's when good leaded Premium became scarce I had this same serious problem and my solution, at the time, was to install a set of "Low Test Base Gaskets", a BMW part that lowers the CR from 9.6 to 8.6 (-ish) and allows the engine to run happily on Regular. You take a slight hit in performance and gas mileage, but not a devastating one. Last year I did a top end on my R60/5 and did (my one last) performance mod on it: went back to the normal, high-compression base gaskets and modded the heads for dual plugs.
So now that you're back to higher compression, what do you do about the pinging?
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Old 07-03-2012, 01:04 PM   #22
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The dynamic timing mark should be centered or slightly below center in the window (on or slightly retarded).

Dual plugging will mitigate pinging.
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Old 07-03-2012, 01:08 PM   #23
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Will investigate. Thanks!!
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Old 07-12-2012, 12:53 PM   #24
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Bill Harris, if you're there... here's an update:

One month has gone by since I last opened my final drive and transferred some oil back into the shaft housing. There is no evidence of leaks or overflow like before, but I did it again today - bike on center stand, propped so front wheel is on the ground. Opened the FD and sucked a bunch of oil out with a big syringe. Put the rear wheel back down, and re-filled the FD to the correct level, leaving about 30 cc's in the syringe, which I dumped back into the shaft housing. This sounds about like the numbers you've experienced, yes?
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Old 07-12-2012, 08:36 PM   #25
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I have the same bike and have also had to deal with the infamous pinging. If you want to be sure if it's pinging lug the engine in 4th or 5th and then whack the throttle. Did the sound get a lot worse? If it did, it's pinging. It sucks.

To be honest, it has taken me several years to get it to completely go away. It was very bad at first but I refused to give up on it but also refused to spend the money to get it dual plugged (everyone seemed to think this was the only solution). I tried the cylinder base gaskets but they just seemed to make the bike lazy. I'll spare you all the details of everything I tried and get to what finally worked. Here is what you need...

1. Timing and valves have to be spot on.
2. Carbs have to be properly synched. This is a bit of an art with these small carbs because you have to do it by ear using the shorting method. Be patient, it works, you'll get good at it. You'll also know when it's right. Do a lot of reading or get someone to show you how the first time. It's important if you want it to run smooth.
3. There are two kinds of springs for the centrifugal advance unit. Get the heavier ones if you don't already have them.



4.Now look at the picture below. See the little brass "collars" around the posts that hold the springs?



They are the magic ingredient! The combination of those and the heavier springs change the advance curve enough to COMPLETELY eliminate the dreaded pinging these otherwise great little bikes are so hated for.

The problem is I have no f-ing clue where to get them...Maybe someone here will know. I got mine with a used advance unit from ebay.

Forget about all the additives and expensive/complicated solutions and track down a pair of these babies. You'll be glad you did. That R60/6 can be a sweet little ride once you get it all sorted.

Good luck!

photorider screwed with this post 07-12-2012 at 08:44 PM
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Old 07-12-2012, 09:47 PM   #26
Bill Harris
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That is the ticket-- I did that on my R60/5 when I went from the low-test base gasket back to the normal base gasket (8.5: to 9.6:1 compression ratio) and dual-plugged it. Able to run Regular gas on a high compression engine.

This is the simplified list of what does what:

Quote:
/5 parts:

12 11 1 356 286 advance unit 1970 - 09.74 $ 277.00
"-007" unit faster advance

12 11 1 356 546 advance units spring 1970 - 09.74 $ 12.25
"lighter spring"

==

/6 parts:

12 11 1 357 626 advance unit 09.74 - 1978 $ 275.00
"-010" unit slower advance

12 11 1 357 627 advance units spring 09.74 - 1978 $ 10.25
"heavier spring"
the "-007" unit and "-010" unit refer to the Bosch part number on the advance unit (the photo above shows a -012 advance for example).

I went with the -010 advance unit with -627 springs to slow the advance curve. With dual-plugging I did not need to limit the total advance. I do retard the timing by 2-3 degrees.

Available from Hucky, http://bmwhucky.com/



Mattz: yep, you'll transfer an ounce or two (30-60cc) of oil.
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Old 07-12-2012, 10:18 PM   #27
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Re mpg...new needle jets should help. Cheap and easy.






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Old 07-13-2012, 08:04 AM   #28
mattsz OP
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Originally Posted by boxerboy81 View Post
Re mpg...new needle jets should help. Cheap and easy.

boxerboy-

Thanks! But... can you be more specific? Sorry about my ignorance, but I'm new to all of this. My check of microfiche parts lists shows a "main jet", an "idling jet", a plain ol' "jet", and a "float needle". Not sure which one of these is a "needle jet"...
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Old 07-13-2012, 08:33 AM   #29
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Ok - pinging...

Thanks, Photorider and Bill, for the continued help with all this.

Photorider - are your magic brass collars permanently attached to the spring posts? If not, can they be removed and measured? Not really expecting you to do it... in fact, please don't - let's not fix what ain't broke. But if they are removable, someone must have an idea of the dimensions of them. It would be an easy thing to machine them, especially if they're made of brass. In the photo, they look to be about the same inner and outer diameters, but one looks taller. I just checked ebay and found three of these things; *none* has the brass collars.

Bill - I'm going to make some assumptions here; please correct me if I'm wrong. Since I have a 1975 /6 bike, I'm going to ignore your /5 parts list. It seems like only one advance unit and spring "weight" is specified for my bike, so is it likely that there could be a different one currently installed? It seems like you're suggesting that I don't change anything - as long as the correct parts are in fact installed on my bike.

Do you know anything about Photorider's magic brass collars, Bill? It looks like their function is to reduce the travel of the weights - they rest a little further out from the unit's center of rotation, and they won't swing out as far when the thing starts spinning. Is there more to this?



As an aside - $275 for that advance unit?!? Really? How often do these things need to be replaced? Dual-plugging labor is probably cheaper! Well, maybe not - like I said, I've got ignorance to spare.
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Old 07-13-2012, 08:42 AM   #30
Bill Harris
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#14 and #11 on the attached schematic.

#14 is the slide needle in the first drawing.
#11 is the needle jet in the second drawing.

The slide needle fits in the vacuum slide and moves up and down within the needle jet. Both wear with time, upsetting the mixture. That needle and needle jet are different than the float needle (#14 in the second dwg) in the float bowl. Meh.





From MAX BMW

I can't find a good, single schematic of the carb, sorry.
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