TGPI switch has been intermittently playing up so I decided to see it they are still available new. None in OZ, Motobins none but Motorworks reckoned they could source one it took a bit of time but it has just arrived, dear little sucker. As parts seem to be getting thinner on the ground these days I added a couple of the plastic bits that seem to get effected by the OZ sun. So I've now got to set aside a day to remove the swing arm assembly, a pity it didn't arrive before the workshop day as that would have kept the Kronies amused. I might do a pictorial on how to do it. I am going to do it the hard way and remove the swing arm. However I did see a post somewhere stating that it can be done on a bike lift without having to remove the swinging arm. Has anybody had success doing it that way? 
Regards Martin.

You’re lucky! You’re showing the new style with the black connector. When I replaced mine summertime last year, I found out then that I had the old style white connector-can’t plug the different types together. Luckily Motorworks was able to provide me with a section of the harness side too with the other black connector which I then soldered to my existing harness. Used shrink tube on the solder joints.

My original got wet and took a solid 2 weeks before it started working reliably again. Upon removal I found 2 large splits in the rubber casing. I had already prepared myself and had everything ready to go. I removed my swingarm to do the work. 

I don’t see the gasket for the GPI or is there one on the original?

I didn't order the gasket but I can make one if needed. I'm going to put the bike on the work table and have a good look but I don't believe I can successfully remove it without removing the swing arm.
Regards Martin.

Swing arm off....

My ex BMW guru friend passed away last week and he had every K trick in the book and more that he had learned over the years.

So, swing arm off and you can meet problems on the way in. 

I have a gear position switch here for my 83 RS, 2 things on it not working, the indicator switch and the temperature gauge. Too lazy to pop the switch in.

I've had good luck repairing those switches, five of them so far.  The major problem is the potting compound that was put around the wires cracking and letting water carry dirt(and salt) into the switch corroding the internals and making electrical contact wonky. 

Once the switch is on the workbench you can take it apart while being very careful to not lose the tiny springs and contact parts.  Several good doses of Deoxit scrubbed with a toothbrush(use your wife's, Deoxit tastes terrible, you don't want it on yours).  Be especially fussy in cleaning out the holes the contacts and springs live in.  There is electrical contact at the bottom.

The important part is to remove ALL the old, crumbly potting compound.  It pays to take your time here to get every little bit.  Again, your wife's toothbrush will help a lot.  Soak the part in 91% rubbing alcohol and scrub it well a couple times then let it dry overnight.  Mix up some slow cure epoxy adhesive and put it around the wires where the old potting was.  Use a toothpick or wooden match stick to work it in to all the nooks and crannies and to get the air bubbles out. 

After the epoxy cures for a day or so, reassemble the switch using a shot of Deoxit to leave an anti-corrosive film on the internal parts.  Don't use any grease as it will interfere with the spring pressure that makes the internal contact in the switch.  Wrap the switch with a layer of Self-Amalgamating tape to seal it.  Reinstall with a new gasket and fillister head(Allen) screws which are infinitely easier to work with than the Phillips head screws the factory used.   This should give you a switch that will outlive the rest of the bike.

Thanks fellas. I've had the swing arm off a couple of times  in the 20+years that I've owned her. The first time I took the trouble to waterproof the switch with red Plasti Dip ( faster gear changes). It will be interesting to see how the Plasti Dip has held up.  The question now is do I fit the fit the brand new switch or do I recondition the old one. Either way the switch will outlast me. 
Regards Martin.

MartinW wrote:Thanks fellas. I've had the swing arm off a couple of times  in the 20+years that I've owned her. The first time I took the trouble to waterproof the switch with red Plasti Dip ( faster gear changes). It will be interesting to see how the Plasti Dip has held up.  The question now is do I fit the fit the brand new switch or do I recondition the old one. Either way the switch will outlast me. 
Regards Martin.

You started the post by saying the gear position indicator had been playing up and that you had got yourself a nice shiny new one…that would be enough for information for me to answer your last question! 

Changing the GPI is a fairly straight forward job, it just needs the removal of quite a lot of work-in-way. I have tried doing it with the swing arm in place and was frustrated. I found the easiest (and quickest) way by far is to remove the swing arm and all that entails…with the added bonus of “while I’m in there” greasing of drive shaft splines, cleaning up the swing arm pivot (Dai mentioned problems with that in another recent post) etc. Having gone to all that trouble of stripping down the back end of the bike…why wouldn’t you fit the new GPI, if you have it to hand? I would, however, and in slower time…recondition the old GPI - they are not complicated units and a bit of drying, cleaning and de-oxit before resealing it gives you a come-in-handy spare…just in case.

The attached link was my effort at understanding the GPI a few years back
https://www.k100-forum.com/t10495-gear-indicator-board-for-1985-k100rt-instruments#124102

Thanks BAE I'd pretty well decided to go with the new one and seal it.  The advantage of the Plasti Dip is that it can be easily chemically removed. However if it has degraded I'll use something else. I've already had a mates one apart and had no trouble with springs and pin ejecting, they stayed in position.
Regards Martin.

MartinW wrote:I'm going to put the bike on the kitchen table and have a good look but I don't believe I can successfully remove it without removing the swing arm.

Good luck.

TacKler wrote:

MartinW wrote:I'm going to put the bike on the kitchen table and have a good look but I don't believe I can successfully remove it without removing the swing arm.

Good luck.

Wow!
I have read many of the posts on different style lifts, but never did I think of this simple one.

You have do do it in stages onto a trundle bed then the couch to a couple of chairs and finish on the table.
Regards Martin.

MartinW wrote:You have do do it in stages onto a trundle bed then the couch to a couple of chairs and finish on the table.
Regards Martin.

Yes. No K-bike klean and jerk!

And use the trundle bed for a lie-down from all the effort when it's done.

I am going to hopefully tackle the job on Tuesday. And my work table is a bed. Piccies on Tuesday.
Regards Martin.

Iorning board for a ramp then ride the bloody thing onto the table. SAFETY NOTE avoid contact with overhead light fitting

Shep wrote:

TacKler wrote:

MartinW wrote:I'm going to put the bike on the kitchen table and have a good look but I don't believe I can successfully remove it without removing the swing arm.

Good luck.

Wow!
I have read many of the posts on different style lifts, but never did I think of this simple one.

Practice...practice.....  



(Yeah, that is in my house   )

What the hell is an an ironing board.

MartinW wrote:What the hell is an an ironing board.

The Christmas gift your wife is dreaming of.

Thanks Gryph I was wondering what to get her.
Regards Martin.

I buy my own xmas presents in July.
I'm old enough to forget in Dec what I bought anyway

Thanks Martin and the rest of the team for this timely info on GPI.

I just returned from a rather wet ride down the south coast of NSW last weekend and when I was a few kms from home on Sunday afternoon the gear position indications on the instrument panel went crazy. I had been riding in rain for most of the weekend and had crossed a couple of flooded causeways. The last 100kms to home was in heavy rain.

Initially I thought that there may have been moisture in the connector on the back of the instrument binnacle. After reading your posts it appears quite likely that my GPI may have got wet inside during the journey. 

I think I'll try to source a new GPI switch as per Martin's post and then have a go at repairing my old one to keep as a spare. The annoying thing about all of this is that I just had the rear end out of the bike to replace the rear main seal a few weeks ago. At least I'm getting good at removal of all the ancillary bits.

I think I'll avoid the ironing board and just jump her (the bike not the wife) straight onto the kitchen table. 
My wife is a bit possessive about the ironing board
LeonW

We did the TGPI switch swap yesterday arvo. SSD came over and it ended up taking around 4 Hr's. We had to disassemble a fair bit of the bike. We had to remove the battery, rear wheel, rear caliper, final drive, driveshaft, LH and RH footplates, and finally able to remove the swing arm. As with a lot of jobs it could have been done quicker spent a bit of time trying to adapt the 1/4" dive tension wrench to a 3/8" drive Allen key until I found a 1'4" drive Allen key in a mini socket set. A couple of other things also slowed us down and I took the opportunity to clean and grease the splines. The Plasti Dip sealant had held up extremely well for the 15 years that it was in there. I'll pull it apart and see why it was getting intermittent problems, but I'm pretty sure it will turn out that it just needs the tracks cleaning.  The lift table is a highly modified hydraulic hospital bed that I scored off a mate and proceeded to do a chop job on. It still needs a few more mods as in the front wheel clamp.
Regards Martin.



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Your lift looks as though you can ride your bike on to the lift and get your feet down on the platform to balance the bike on the platform. The lift I bought from Princess Auto has no room on the platform for your feet so you need two strong men or women to push the bike on to the lift.
Always can find a good deal at PA but it may not always be the best tool.

It's 725 x 1965 not including the ramp, the deck height 650. I made it wide enough to get both feet down and the side stand. I also had to design it so that it's at an angle in the down position to allow for the jack, and when fully up the deck it's parallel to the ground. I made scale models out of Balsa wood to get all the angles and pivot points right. I'm currently looking at redesigning the front wheel clamp currently made out of dumbbell bars so that it can actually hold and lock the bike in an up right position. Also looking at supports when it's up rather than the saw horse and the stool.
Regards Martin.

Martin you did not say if this fixed the problem

It's too bloody wet to go for a ride but going through the gears stationary it seems to be cured. We have the start of a small lake in the backyard,  I may look at buying a boat.
Regards Martin.

a new mod for the 75 ? Floaties on the foot pegs ?

Weather cleared today so I took the Brick for a road test. TGPI works fine for N, 2,3,4,5 however when supposed to be in first it will show blank or 3, mainly blank. A couple of times  it did show 1st but some of those times it was a false neutral caused by me not fully engaging the gear while trying to get it to work. I'll contact Motorworks to see what they say. It's going to be a pain to go back in there , I've mulled over with just living with no 1st indication in the hope that with a few more K's under it's belt it might come good. However I also might open up the old one to see if it's repairable as a back up.
Regards Martin.

That's a bit annoying Martin. There's a fair investment in time and money getting that new TGPI from Motorworks, fitting it etc.
I was going to buy one for myself but will wait for your next update.
By the way, it was sunny in sunny Goulburn today also.
Cjheers
Leon

I rang Motorworks UK yesterday evening and had a good talk with a very helpful Sid. I explained the problems and he said that he had never encountered my problems before. He knew what he was talking about and was going to confer with other staff try and find a solution, it's good when you get knowledgeable helpful staff. As it stands at the moment I'm going to look at a few things at my end and keep riding it with the hope that whatever is causing the problem rectifies itself with use. 
Regards Martin.

I just received the following message from Motorworks.
Hi,
We are sorry to hear that the new gear position switch you purchased has not fixed the problem.
Unfortunately we will have to ask you to return the part to us so we can send it to BMW.
Please return the item to the address on your invoice and include the return reference SR045474
 
Kind regards,
Sid
Motorworks

MartinW wrote:Weather cleared today so I took the Brick for a road test. TGPI works fine for N, 2,3,4,5 however when supposed to be in first it will show blank or 3, mainly blank. A couple of times  it did show 1st but some of those times it was a false neutral caused by me not fully engaging the gear while trying to get it to work. I'll contact Motorworks to see what they say. It's going to be a pain to go back in there , I've mulled over with just living with no 1st indication in the hope that with a few more K's under it's belt it might come good. However I also might open up the old one to see if it's repairable as a back up.
Regards Martin.

Before you go through the nausea of taking the GPI off again…have you tried checking for continuity using a test meter on the GPI plugs (you can do both the LCD and the GPI itself this way). As per my post I linked in my previous message (post number 7 above), do you have any misalignment of the GPI switch? Mine was off by a tiny amount, but that was enough to give a blank reading in 1st. Unfortunately, to fix it, you do need to tear down the back end again…but could save postage/delay of returning the unit to the UK

I just tried a switch that I refurbished for a mate and it shows all the gears. However I'll try the alignment when I get back in there but I can't really see how it could be misaligned by that much time will tell. I pulled apart the switch that was removed and it's very dirty as compared to the refurbished one. So at this stage if realignment doesn't work I'll clean up the one I pulled off and refit it. 
Regards Martin.

Jamie64 wrote:a new mod for the 75 ? Floaties on the foot pegs ?

With some of our weather lately, I’ve been contemplating replacing the final drive with a propeller drive . . .

Bill

LeonW wrote:That's a bit annoying Martin. There's a fair investment in time and money getting that new TGPI from Motorworks, fitting it etc.
I was going to buy one for myself but will wait for your next update.
By the way, it was sunny in sunny Goulburn today also.
Cjheers
Leon

My success rate in resurrecting these is 100%, so when you get it out I’ll go on an excursion of a few blocks to your workshop. 
I know wher you live. 

Bill

I'm about to clean up the one that I removed, however I'm unsure as to lube the contacts with a slight smear of contact grease or a thin coat of LPS 1. I can start on pulling it apart again on the deck or wait till this afternoon until SSD comes over and put it on the lift table. It's easier on my old back on the lift however it takes two people to tie it down on the lift and deploy the centre stand.
Regards Martin.

I didn't put the bike on the lift and cheated by not removing the battery to get the wire through. I removed the battery clamp and chocked up the battery with a couple of blocks of wood. It took and hour to get to it and remove it. I loosened the bolts and tried to rotate in in both direction still no 1st indication. I put on my mates one and it showed all the gears. I then tried the one that was on there pulled it apart and refurbished, it showed all the gears. If you rotate the new switch with a screwdriver it will show all the gears but not when it's mounted. I tried it a couple of times and then decided to just mount the refurbed one. It's as if it's slightly out internally. It took 1.5 Hrs to get it back together. I went for a run and the newly refurbed one is spot on. I went up and down the gears and everything showed correctly.
Regards Martin.

If it shows "3" or Blank then the problem is with the Yellow / Black and Yellow / White contacts in that particular switch orientation.  Based on your statement that all the other gears indicate correctly including neutral, the problem is strictly limited to those wires in that switch orientation.  What's supposed to happen is that the wipers are supposed to contact the fixed copper contacts attaching to those wires I mentioned. In your case, contact is not being made for Yellow / Black and is intermittent, so sometimes Yellow / White makes contact (and you'll get a "3") and sometimes it won't (and you'll get a "7" which shows up as a blank).  It is most likely oxide on the copper strips in that one part of the switch mechanism which is preventing the contact.  You'll have to get inside the switch and somehow clean it up.

As for putting grease of sorts on the wipers, that IMO is a bad idea.  The best is to ensure the copper contacts and wipers inside the switch are clean and shiny by using dioxin.  A grease is not a good conductor and may cause problems with such small currents that are drawn by the OEM gauge cluster in this application.

Thanks Rob however it's a brand new switch from Motorworks UK, I've contacted them and they want me to send it back, which I'll do on Monday. If I pull it apart I'll void the warranty.  The new one would show 1st if manually rotated with a screwdriver  but not when installed on the transmission, so possibly a partially dirty track. I did pull my old one apart and cleaned it but I didn't grease it. As per the posted picture it was pretty grotty. The old one is currently fitted and working perfectly. Mates reconditioned one also works fine.
Regards Martin.

Sidecar paul had a bit about those switches. He put some resistors in somewhere so as to have a continuous current. I cant find it but it was probably 6-7 years ago.

Thanks Rick I saw your 75 up for sale. I don't think I could part with mine. At the moment I'm just happy to not have to go in there again, I hate doing jobs twice.
Regards Martin.

RicK G wrote:Sidecar paul had a bit about those switches. He put some resistors in somewhere so as to have a continuous current. I cant find it but it was probably 6-7 years ago.

Yes Rick, it was actually 8 years ago, so to refresh your memory have a look here:-

Gear position switch. (k100-forum.com)

PS Both my K's have been running this mod since the '80s without any gear indicator issues.

Paul.

Thanks Paul I've saved a copy of your drawing in case it plays up again. The new switch is on it's way back to the UK. The old reconditioned switch is functioning fine.
Regards Martin.

ive got the same problem , with gear indicator only displaying 3rd from 1st through to 3rd and nothing for 4th and 5th , and no neutral indication . i get an intermittent  2nd when riding around sometimes . i have 2  k75 , one runs perfect the other just has this gear indication problem . so i started swapping parts from bad bike to good bike and running them to test the parts , everything worked fine on good bike . so no problem with gear position sensor or breadbox , conclusion was wiring harness fault/short somewhere . so i swapped the harnesses over and sure enough the problem swapped over also .

I just got an Email off Motor Works giving me a full refund for the switch and the freight both ways, so happy.
 I don't know whether I'll try and order another switch as my refurbed one is functioning fine and has been re-waterproofed.
Regards Martin.

It is wonderful when a business treats you properly as a customer.
Obviously a good company to deal with.

I have one in my shed that I got for my 83 RS.....I havent got around to fitting it but looks like I should. I put one in my RT in 2014 and no issues.