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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Classic Motobricks => Topic started by: stokester on May 04, 2019, 03:17:27 PM
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Since last fall I’ve had my ’93 K75S with 78K miles in its mid-life refresh. After an unexpected ride into a ditch at the RA rally in PA along with an pesky oil leak from what appeared to be the rear main I decided that this would be a mid-life refresh since I’m fortunate enough to have not only another K75S but a couple of airheads to ride.
So, these are the things I’ve done:
- rear main seal
-clutch
—- clutch o-ring
—- spring
-- - clutch plate
- fuel line from fuel pump regulator (cracked at bends)
- vacuum line from FPR
- tank filler seal
- radiator cap seal (both)
- set valve clearances (found two intake needing next size adjustment)
- clutch lever bushing was worn and replaced
- replaced fan with a Spal unit from tills.de
- spline lube with Guard Dog
- clutch spline lube with Guard Dog
- fuel injectors replaced with units cleaned and checked by Mr Injector
- starter cleaned
- found the rear brake lever return spring missing? installed replacement
Within the last couple of years along with regular maintenance I replaced the original brake lines with a Spiegler SS set, the Performance shock with a YSS unit from Ted Porter’s Beemershop , odometer gears and a new Odyssey battery.
I inspected the tank to find it clean and the fuel pump damper in good shape so it was not replaced. The clutch components were obtained from a motobrick member so I replaced them although the friction disk was well within spec and not oil soaked. A test ride and extended idle caused the fan to turn on and it appears that it pushes more air than the stock unit.
An online friend of mine from another forum made me a seal driver for the rear main to allow for the .5mm proud seal setting and another member of that forum send me a pair of Oetiker clamping pliers he did not need so I was able to replace the original clamps. Those along with a clutch alignment tool from Beemerboneyard allowed me to do it all with no issues.
So after a couple of shake-down rides it has all been good and I expect this refresh to last me for at least another 78K miles. I am thankful for Beemerboneyard, BMW, tills.de, Ted Porter and others for having the parts available for a 25 year-old motorcycle and the many Motobrick riders who provide their insight and experience to the web. I hate to think what it would have cost to have all this done at a shop.
Ride Safe
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Yes, bricks are like chicks...
...They love it when you fuss over them.
Enjoy the ride this summer.
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Fantastic and worthwhile work to keep the K on the road. Congrats!
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maintenance is good!
nice thread title... :bmwsmile
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maintenance is good!
nice thread title... :bmwsmile
Title just slightly modified... :2thumbup:
Based on what I found a K75 with good maintenance will probably need a refresh near the 75K mark.
Probably not to the extent of my work but for those that are monitoring, I found the following are in need of inspection...
- if leaking, the clutch o-ring and/or the rear main seal
- water pump seal if leaking (mine was a few years ago)
- fuel line to fuel pump regulator (mine had cracking at the bends)
- fuel pump regulator vacuum line (mine was very stiff and not pliable at the FPR)
- starter cleaning (easily done and prevents future issues)
- valve check (remember that Yamaha and Kawasaki both use 29mm shims too)
- cooling fan (mine worked OK but I found it squeaking after removal)
- odometer gears will probably fail sooner or later
- fuel injectors (Mr. Injector will flow check and clean for a very reasonable price)
- check fuel pump damper (mine was OK)
- brake lines (they can deteriorate internally and Spiegler makes a great SS set)
This also includes the mandatory spline lube which is part of every rear tire change and along with regular oil/filter, coolant and brake fluid flushes makes for a happy Motobrick.
While all of the items were probably not necessary, it can only contribute to my many trouble-free K-bike miles.
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great list.