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1973 R75/5 Back-to-road Project

You could also go for the BMW sport springs with part number ending in 017. They are actually shorter than the stock springs, making them easier to install. They're made out of a heavier gauge wire. The soft springs probably have a dab of yellow paint on the end. The sport springs have white paint.
I've had a sort of problem with the Progressive springs in that they tend to bind. Also, they come with spacers that are not really needed and make them a bear to install.

I stand corrected. I didn't get the progressive springs, but the heavy duty (sport) springs from BMW as mentioned by Boxerbruce above. They have a white dot at the top. But I still haven't decided, will I need the spacer or should I go without? I am on the tall and heavier side, 6'1 and 210 lbs, if that makes a difference on selecting fork stiffness. Thanks!
 
Did the original springs stick up outside the fork tube when the top cap was removed? Where will the top of the new spring be when installed? Obviously, there needs to be some compression on the spring...there is a sag height. From memory, the difference between the bike sitting on the tires (no centerstand) and you sitting on the bike (feet on the pegs) should be around 2-3/4 to 3 inches. According to the basic specs, the front suspension travel is about 8.2 inches. I believe the sag should account for about 1/3 of that distance.
 
Did the original springs stick up outside the fork tube when the top cap was removed? Where will the top of the new spring be when installed? Obviously, there needs to be some compression on the spring...there is a sag height. From memory, the difference between the bike sitting on the tires (no centerstand) and you sitting on the bike (feet on the pegs) should be around 2-3/4 to 3 inches. According to the basic specs, the front suspension travel is about 8.2 inches. I believe the sag should account for about 1/3 of that distance.

The old springs stuck out of the top just a tiny bit, less than 10 mm or so. I just realized that my fork seals are leaking and since I will have to go in again anyways, I will just use a 2 inch spacer for now, then test free sag and loaded sag with the springs and spacers installed and can adjust the spacer when I do the seals and steering bearings.
 
Springs

I stand corrected. I didn't get the progressive springs, but the heavy duty (sport) springs from BMW as mentioned by Boxerbruce above. They have a white dot at the top. But I still haven't decided, will I need the spacer or should I go without? I am on the tall and heavier side, 6'1 and 210 lbs, if that makes a difference on selecting fork stiffness. Thanks!

OOPS. I may have forgotten to mention that these springs are shorter than the standard springs and made from a heavier gauge wire. You don't need a spacer on a bare bike but may use one if you're running a heavy (Vetter, Luftmeister, Rabid Transit) or such fairing.
 
Oilpan is next

OOPS. I may have forgotten to mention that these springs are shorter than the standard springs and made from a heavier gauge wire. You don't need a spacer on a bare bike but may use one if you're running a heavy (Vetter, Luftmeister, Rabid Transit) or such fairing.

My plan is to fix the fork seals first, measure free and loaded sag and get an estimate that way. I prefer a stiffer suspension, so I maybe ok with the spacers. They were actually 1 inch, not 2 inch as mentioned above.

While I am waiting for the seals and steering bearings and the bearing puller tool I'll drop the oil pan and change the oil again. Seems straight forward to me, I know not to over-torque the bolts down there (got me an inch-lbs torque wrench!) and check the metal sieve/filter in there. Anything else to watch out for? I also updated the website with my fork spring replacement documentation, if you are interested.
 
Check the bolts holding the pick-up tube/strainer and make sure they are not loose. This is a known problem. If loose, a little blue loctite wouldn't hurt....
 
I'm not sure if you'll find this useful, but I just went through the process of pulling the flywheel on my R90/6 because it was installed incorrectly (it was oriented one bolt-hole off by the P.O.). Anyway, the same steps apply to getting to the rear seal and I find it helpful to have a list of the steps as a guide...

  1. Remove fuel tank (disconnect fuel lines, unscrew plastic nuts at rear of tank)
  2. Remove L&R side panels
  3. Disconnect the negative lead of the battery
  4. Remove front cover
  5. Remove spark plugs (easier to crank the engine over)
  6. Use allen key in generator to rotate engine CW while carefully inserting a chopstick through the spark plug hole to find TDC of the compression stroke
  7. Verify that the TDC is coincident with "OT" on the flywheel as seen through the timing access hole (If it is not then the flywheel has been installed wrong)
  8. Remove left and right side airfilter cover (you need to loosen carb boots). After the covers are off, reinstall carbs to the cylinder head and cover the carburetor openings
  9. Remove choke from left-side air filter cover
  10. Disconnect positive lead on battery
  11. Remove battery and battery tray
  12. Remove hollow, ground-bolt on transmission and negative battery lead
  13. Drain drive-shaft oil
  14. Loosen drive-shaft boot clamp on transmission and slide drive-shaft boot off transmission-side toward the swing arm
  15. Remove four bolts (10mm, 12-point wrench, use rear brake to keep shaft from rotating, replace with new, shorter bolts, no lock washers)
  16. Remove rear brake pedal (discconect brake rod from rear drive, remove brake assembly from frame)
  17. Remove shock absorber bolts (bottom mount only)
  18. Remove rear wheel (loosen nut on right side, loosen pinch-bolt on left side, tap out axle and remove wheel. May have to deflate tire if oversized tire has been installed)
  19. Disconntect brake switch leads
  20. Remove swing-arm (use modified 27mm socket to remove axle nuts, remove axle pivot screws 8mm allen wrench)
  21. Remove clutch arm from transmission (remove cable, remove circlip - use thick feeler gage to bias clip, then use screwdriver to pry it off)
  22. Disconnect leads from neutral switch on bottom of transmission
  23. Remove transmission bolts (3 bolts, one nut)
  24. Remove clutch (6 bolts, remove three bolts completely, then install long bolts with nuts, remove second set of three bolts, then back nuts off to relieve pressure on the diaphram spring)
  25. Block the crank before going any further!
  26. Remove flywheel (5 bolts, use tool to keep flywheel from rotating.)
 
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This is also helpful sometimes...(R90/6)

M6 nut on the end of the automatic advance unit on models through 1978: 4 ft-lbs (48 in-lbs)
Flywheel Bolts (5): 11mm, 75-80 ft -bs (11mm bolts can be reused if in good condition, 10mm must be replaced every time)
Clutch bolts (6): 15 ft-lbs (Blue Loctite)
Transmission to engine (4): 15 ft-lbs
Clutch arm axle - replace with new-style axle (headed-axel and new type of retaining clip)
Driveshaft U-joint bolts (4): 12pt, 26-29ft-lbs MAX, buy shorter version of bolts with NO lock-washers. Both bolt & flange threads must be clean and dry + Blue Loctite on the bolt threads.
Swingarm pivot pins (8mm Allen wrench): 7.5 ft-lbs (15 ft-lbs first, then loosen and retighten to 7.5 ft-lbs, center swingarm to within .020")
Swingarm nuts (27mm, special socket): 72-75 ft-lbs
Rear Axle (22mm, nut): 25 ft-lbs
Rear axle (22mm): 25 ft-lbs
Clutch arm axle - replace with new-style axle (headed-axel and new type of retaining clip)

This was the first time I'd done any major work on the bike so if any of you with more experience want to make corrections or add something, please feel free.
 
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This was the first time I'd done any major work on the bike so if any of you with more experience want to make corrections or add something, please feel free.

Very helpful, thanks! I will do this work in the next months and will add to this, if necessary.
 
Clutch arm

Just so you late model folks know: The clutch pivot pin on a 4 speed is held in place with a cotter pin. You have to use just the right size, metric of course, to fill the hole that it goes through and it corresponds with a notch in the pin. The neutral switch wire is on the back of the 4 speed transmission on the cover, not on the bottom.
 
Just so you late model folks know: The clutch pivot pin on a 4 speed is held in place with a cotter pin. You have to use just the right size, metric of course, to fill the hole that it goes through and it corresponds with a notch in the pin. The neutral switch wire is on the back of the 4 speed transmission on the cover, not on the bottom.

Thanks and good point - I'll edit my post above to reflect a R90/6...
 
Cycle Works

I have placed an order with Cycle Works on Nov. 2 (9 days ago), I received an order confirmation but nothing since then. I know they are a small shop and it may take a bit longer to ship, so I sent another email 2 days ago but no reply.
I am not worried, just need my stuff to keep wrenching. Has anyone else had a similar experience with them?
 
I have placed an order with Cycle Works on Nov. 2 (9 days ago), I received an order confirmation but nothing since then. I know they are a small shop and it may take a bit longer to ship, so I sent another email 2 days ago but no reply.
I am not worried, just need my stuff to keep wrenching. Has anyone else had a similar experience with them?

My personal experience was from one order. I placed the order, didn't hear anything for a few days, so I sent an email. I got a prompt answer and had my tools a few days later.

Having said that, there are at least two threads on another site asking the same question. The responses seem to follow a similar theme - one-man show, poor communication and follow-up, but the tools are good and the orders eventually get filled.
 
Oil pan and strainer

I removed the oil pan and strainer to check for any debris, but everything looks sparkling clean!

However when I removed the oilfilter (which I had changed 3 weeks ago) I realized that the rubber seal on the outside had disintegrated. Could it be that I have not lubed it with engine oil before installing the inner cap (I don't remember if I did)? Or could there be any other reasons?
 

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Looks like too much compression on the outside o-ring. It's important to make sure that one of the inner o-rings didn't remain at the base of the pipe. Sometimes they get hung up inside.
 
Looks like too much compression on the outside o-ring. It's important to make sure that one of the inner o-rings didn't remain at the base of the pipe. Sometimes they get hung up inside.

I just checked, but nothing there. My only explanation now is that it was sticky when I put the inner cap on and got destroyed they way. But I don't know.....
 
Do oil filters have a shelf life?

My bike came with two extra oil filters, date stamp says 10/2010 (if I read it correctly). Can I still use them? They look brand new to me, were stored inside a garage by the previous owner and even the box they came in looks like new. Definitely no damage from water or humidity.
 
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