Thank you for allowing a newbie, and introduction thread with easy questions

[brant914]

Hello Everyone!

I'm Brant.
brand new to bmw motorcycles
I just started taking one apart and pulled the motor yesterday
I have A LOT to learn and a lot to research

so far though its been a good experience with lots of resources and knowledge out there
the bike shows a registration from 1992, and I know it went to texas, Kansas, and then Colorado before I got it.

I do think I likely found the problem that may have taken it off the road in 1992
I found the points wire pinched in the cover and as flat as the wire is, I'm sure its broken internally

Anyways, I have a lot of questions and will try to not bore everyone with repetition
I would love to throw a few out that have me stumped currently:

-did the 1971 bikes have the chrome side (battery) covers. I'm thinking not on the SWB models, but not certain yet

-is there a source for the tool box? My bike came with the seat mounts ripped from the rear subframe and very little of the original attachments
I need to figure out how to replace the seat mount hardware, seat lock hardware, battery box, tool box, etc...

- do people ever polish the aluminum wheels. all of my spokes are tarnished, and I figured I need to get a professional to re lace the wheels.... maybe I'll polish them prior to sending them out?

- does anyone recommend a wheel lacing and balancing shop? I can go to a local motorcycle shop (Kawasaki) I know well... but wasn't sure if this might be an item that is worth sending out to a bmw pro

-valve covers..... well one of mine has an internal crack. oddly the crack is on the top side of the valve cover. I assumed the bike had been layed over, but once I realized the crack was on the top... I have no idea. I'm really curious about how to read the date codes for manufacture. My pictures are not cooperating at the moment.... but one cover has no date stamp and is probably a replacement. The other has a bmw circle with 72 stamped into it. Is it a replacement also from 1972? or how do I read the date code in the part to know the manufacture date?

thanks again everyone for pointing me in the right direction:

 

[20774]

Welcome, Brant! There should be some great /5 owners along to help with your questions.

I'll take a shot at some:

- side covers: read on a recent thread that no side covers on '70/'71s -- another recent members /5 https://forums.bmwmoa.org/showthread.php?91063-1971-R75-5-questions

- tool box: might be still available from BMW; otherwise, look at fleabay as well as the link in my signature line for the section on used parts suppliers

- wheels: again in my sig line is a section on wheels

- cracked cover: there's no real positive pressure inside the valve covers. I have a crack on one of my R69S covers...it's on the lower side...I have sealed it from the inside with JBWeld

- date code: put your 7 digit VIN near the oil dipstick into this site to find the build date - www.bmw-z1.com/VIN/VINdecode-e.cgi

 

[brant914]

Thanks Kurt!

and thanks for the links and tips.
I will definitely read them!

regarding the manufacture stamp.
most companies put a build date into their parts
I'm specifically curious because one valve cover has a 72 stamped into it
the other nothing...


the bike is 3/71 and the VIN seems to line up with that and looks to be legit.

 

[brant914]

wow Kurt.
you have everything in your signature...
Its going to take me days to get through it all

hey I was told the the cylinders are nikasil?
is that true?

do people ever reuse these.... or will I need to buy new cylinders to get the correct nikasil treatment?

(I have not even taken my cylinders off yet or measured them, but believe I have bad rings)

 

[20774]

If the bike is a 3/71 build and you see a date stamp of '72, then I can only think that it was replaced early by a previous owner.

The '71 bikes did not come with Nikasil cylinders from the factory...they were iron cylinders. Again, a previous owner may have replaced the barrels. That can be done I believe with specialized kits from one or more suppliers. Note that the pre 1976 bikes had engine case openings of 97mm and in 1976 it was increased to 99mm. So, swapping barrels over that timeframe can't be easily done.

Here's a post of mine which shows a standard cylinder (left) with a Nikasil cylinder (right) when I did my top end. The standard cylinder will have a definite dark ring of steel around the edge; the Nikasil is aluminum throughout with the coating on the inside. If yours is truly Nikasil, typically all that would be required is to replace the rings...if a honing is needed, a special set of hones is required in order to not damage the Nikasil coating.

 

[brant914]

thank you again Kurt!

I didn't see the attached picture of your cylinders
I'll take mine apart soon and compare

 

[lmo1131]

Welcome aboard Brant.

One of the cool things about these old airheads is that the valve covers fit anyway you want to put them on (there is no top/bottom), hence why your valve cover has a crack "on top". 1970-1995 covers are interchangeable; the date of manufacture machts nicht.

Be aware that the /5 drum brake wheels are laced with "offset" to compensate for the backing plate, if they are laced "on center", the spokes will touch where they pass over each other.
Ask me how I know this > https://forums.bmwmoa.org/showthread.php?46463-5-Front-Wheel-Offset

You mentioned that your spokes are tarnished... I would have expected them to be RUSTED ... I wonder if they are stainless? Buchanan's is an excellent wheel shop, they re-laced my wheel with stainless spokes.

Many of the dealers share the same "BMW Microfiche" drawings, they're a great source of information, even if you don't buy from them. Seat hinges, tool box, come to mind.

eBay is a good source for used parts once you know what you're looking for. Kurt's resource compilation is outstanding.

 

[brant914]

Thank you!

really good to know about the wheels/spokes/ and offset
woody's wheels are in Denver and about a 45 minute drive from me.
Not sure if they are well respected or skilled.... saw them listed in Kurts resources and called them
I like the idea of driving down, talking to a live person and avoiding shipping.
so I will ask them about the lacing patern for the /5 drum when I go down there in the next week or two

anyone know if they have a good reputation for knowing what they are doing?


valve covers:
oddly... I definitely kept the right and left sides separate as I opened them to adjust the valves

I found the crack and tried to put it back on with the crack down.
no hardware and no torque... but I could clearly see the warp in the cover that it didn't fit flush against the head

I flipped it to put the crack up, and it slid right over the studs and fit tightly against the head

so i'm guessing it may have been cracked a long time ago and flipped a long time ago.
long enough that its taken a set from heat, or warped.

did not want to fit correctly with the crack down (at least not anymore)



by the way....
I think the Clymer manual listed the valve clearances at .008 exhaust, and .004 for intake

is that the correct number?
I say someone mention .008/.006, and wondered if the manual is misprinted or the other post was off.

 

[lmo1131]

.008" and .006"; exhaust/intake respectively.

 

[20774]

Clearances have fluctuated over the years. Initially it was 0.006/0.004 but the post wasn't wrong...0.008/0.006 is your best bet...let's the valve faces sit on the seats a small amount of time longer letting them cool that much more.

 

[ebeeby]

.008" and .006"; exhaust/intake respectively.

6 and 8. On these early /5's, pay attention to the exhaust valves tightening up over time (keep a journal of your lash maintenance). This is because the metallurgy is not suitable for unleaded fuel and the exhaust valve seats on many get beat down. If your exhaust valves do this, you will need to send the heads out for new exhaust valves and seats that are compatible with unleaded fuel (I recommend Ted Porter's Beemer Shop for this work).

 

[lmo1131]

+1 on Ted's shop.

 

[brant914]

Good tip about the heads and valvetrain!

roughly what is the range for a pair of heads to be rebuilt... seats... guides... maybe valves
I'm wondering if I should just do this now when I pull them and re-ring. I'll test them when they are off for seal, but sounds like something to deal with up front and then hopefully be done with.

anyone have a rough estimate for the price of rebuilds?

 

[guenner]

Woody's in Denver has an excellent reputation for their wheel and rim work. Laced and trued my front wheel perfectly.

/Guenther

 

[brant914]

thank you.
good to know.
my first trip there, so best to find someone who knows what they are doing and does it right

 

[20774]

anyone have a rough estimate for the price of rebuilds?

$700-800 with all new parts.