A few questions regarding my 1987 K75s

[cafecubano]

Hello everyone,
I am new to this club and to riding a motorcycle ( about 600 miles under my belt).
I purchased a K75s '87 after doing some homework though I really wanted a '90s model with the low seat and the black powder coated engine parts I had to settle for something within my price range. The bike is in great shape with a great service history.
61k miles on it, A few things that I have noticed and would like to do something about one is the popping noise coming from the 8 month old rear monoshock (progressive 420), it is as if the shock got stuck and unstuck while riding. Second is the rear top case doesn't seem to lock properly so I have to keep it shut with a bungie cord. Third the seat lock is non-existent so I can't keep anything of value under there. I mean the whole lock was just removed. Fourth one of the pannier bags is completely missing one of the two locks.
I realize these are petty inquires but any help would be much appreciated.
My other questions are of proper riding technique. I find at times while riding my shifting can be rather smooth and sweet, but others I can feel my. heart ripping out of my chest :doh. When I slip into false neutral and try to get back into gear any gear without feeling like I'm tearing up the gears. Some times my up shifting is smoother than others. I would like to find a way to keep my shifting consistantly smooth. So far I have found that the shifting process must happen slowly to go smoothly. Is there a certain RPM I should be at before shifting up to the next gear?

any help regarding any of these questions would be very helpful

Armando
http://www.bmwmoa.org/forum/attachment.php?attachmentid=9463&stc=1&d=1185770941

[pvtpepper]

Can't help you on those other issues but shifting a fine pony such as the K75s is straight forward: preload the shift lever with your toe just before you shift into the next gear, just bring up the lever gently till you feel it stop. Ease in the clutch and nudge it up into gear.

I hope I got the explanation right....otherwise I will be pummeled by those more astute.

[breyfogle]

Hello everyone,
....Second is the rear top case doesn't seem to lock properly so I have to keep it shut with a bungie cord.

The lock cylinder is only held in place but a weak plastic nut riding on weak plastic threads. When my topcase lid won't latch, I always find that the nut has worked loose which allows the lock cylinder to move down slightly so that it no longer grabs the locking bar in the lid. Adjust the lock cylinder position, tighten the plastic nut and it should work fine for a few weeks, then repeat .

[JRX111]

I too have a K75s as my 1st bike. Mines a '90. Regarding your progressive shock - it sounds like you have the same issue that I had on my progressive when I first installed it.

If your problem is like mine, the upper coils are getting stuck inside the top cap. What worked for me is to lightly grease the exterior of the upper coils, and the inside surface of the top cap (to the extent that you can reach it).

After that little lube job (4 mos ago) I have had no more sticking problems with the shock.

[byker]

Regarding the top case lock. I have had success with mine by removing the plastic nut and wrapping the thread with teflon tape as used by plumbers. This works for a while, but still needs tightening every so often.

[mieczkow]

You can buy a complete set of locks for your side cases, including both latches and the latch which fastens the bag to the carrier rack for about $60. The replacement is easy - there are some posts on the IBMRW tech section on how to replace these - it's pretty easy - I just did it myself.

[deilenberger]

Top case lock - it's just a PITA.. and no known permanant cure. If you're wise - when you have things in the topcase - also add some strap to make sure it stays closed. It's not a lot of fun being in heavy traffic doing 80MPH with stuff flying out of it 'cause the lid popped open (DAMHIK..)

Seat lock - could this be a low seat bike? If not - and it has the normal seat that pivots over to the right side - you can likely buy a replacement lock assembly - perhaps cheaper from someplace like www.beemerboneyard.com

EDIT - looked at your photo. That's a standard "comfort" seat from BMW. A replacement lock is in order..

Shifting - do the problems occur on upshifts, downshifts, all shifts? Downshifts expecially between 4-3 and 3-2 can indicate the clutch splines need lubrication. The K bike trans isn't the smoothest shifting transmission in the world - more along the lines of a klunk-box - but as others mentioned preload helps, or as I used to do - barely feathering the clutch while shifting... ie - don't pull it all the way in, only far enough to remove power going through the clutch may help.

Rear shock - as other suggested - could be coil binding, but also make certain that the pivot points on the shock are lubricated where it bolts to the bike. IIRC - the 420 used bronze pivot points - rotating in an aluminum housing. Make certain these have a bit of lubrication on them (engine oil works.. a few drops) where they turn in the mount on the shock.

HTH..

[breyfogle]

Top case lock - ...It's not a lot of fun being in heavy traffic doing 80MPH with stuff flying out of it 'cause the lid popped open (DAMHIK..)


Been there - done that, long before this board existed. I thought I was the only idiot to empty his top box at speed on the freeway !! I feel better .

[mrich12000]

Top case lock - it's just a PITA.. and no known permanant cure. If you're wise - when you have things in the topcase - also add some strap to make sure it stays closed. It's not a lot of fun being in heavy traffic doing 80MPH with stuff flying out of it 'cause the lid popped open (DAMHIK..)

Seat lock - could this be a low seat bike? If not - and it has the normal seat that pivots over to the right side - you can likely buy a replacement lock assembly - perhaps cheaper from someplace like www.beemerboneyard.com

EDIT - looked at your photo. That's a standard "comfort" seat from BMW. A replacement lock is in order..

Shifting - do the problems occur on upshifts, downshifts, all shifts? Downshifts expecially between 4-3 and 3-2 can indicate the clutch splines need lubrication. The K bike trans isn't the smoothest shifting transmission in the world - more along the lines of a klunk-box - but as others mentioned preload helps, or as I used to do - barely feathering the clutch while shifting... ie - don't pull it all the way in, only far enough to remove power going through the clutch may help.

Rear shock - as other suggested - could be coil binding, but also make certain that the pivot points on the shock are lubricated where it bolts to the bike. IIRC - the 420 used bronze pivot points - rotating in an aluminum housing. Make certain these have a bit of lubrication on them (engine oil works.. a few drops) where they turn in the mount on the shock.

HTH..


Two weeks ago while driving back to Clinton Ont. From Godrich. Well the lid did open and there goes my $200 dollar glasses. Only realized the dam thing was open half way home . needles to say I went back and looked along the hyway no luck now there is a teather on it ****e ..:banghead :banghead

[Kayseventyfive]

there goes my $200 dollar glasses. ..:banghead :banghead

You guys are making me feel lucky that all I lost was a windbreaker.

.

[crgrbrts]

Perfecting gear changes on my K75S took some practice with quite a few disturbing metal-to-metal clashes along the way. Smooth shifting on this bike is definitely an acquired skill.

The advice about pre-loading the lever is certainly good, although the necessity for quick shifting to meet sudden traffic challenges (especially downshifting) sometimes precludes such finesse.

I upshift by pulling the clutch lever in no more than halfway and thrusting my shift lever up smartly. You certainly can't "snick" it into gear. There's a decided travel and hesitation between 1st and 2nd with neutral being much more obvious than on any other bike I've owned, including later Beemers. When downshifting, I blip the throttle between gears -- especially between 2nd and 1st. This seems to free up the clutch (which is new, by the way) and has eliminated falling into false neutrals and "crunching" into 1st.

I've also found that I often need to either blip the throttle or rock the bike slightly in order to engage 1st gear from a standstill in neutral. That's one reason I always come to a traffic stop in 1st - never in neutral.

Of course, it's entirely possible that my 90K mile machine's gearbox needs a little attention. On the other hand, the eccentricities of my K75S transmission might just be normal. We hear of them consistently.

[breyfogle]

Smooth shifting on this bike is definitely an acquired skill.

K-bike trannies should not require any significant "acquired skill" to shift properly. At 120,000 miles, mine never has a problem finding neutral (rolling or stopped). I typically upshift using a combination of shift lever preload and just a bare minimum of clutch lever travel resulting in an almost Japanese upshift. Downshifts require a bit more clutch lever and usually result in a very positive klunk. No need to blip the throttle when shifting up or down and I don't think I have ever had a false neutral.

It sounds like you have learned to live with your particular tranny's quirks but it also sounds like it is definitely not shifting properly.

[CustomSarge]

AKA silicone adhesive: a smear on the big top case nut both keeps it in place and allows removal. Do a rubbing alchohol wipe on all before application. G.H. <<<)))

[cafecubano]

I just wanted to thank all of you for all your help and replies. :wave
I am very happy to have found this forum. I plan on using it as much as possible to get to know my (new to me) 1987 k75s.