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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: szabgab on November 27, 2018, 06:04:16 PM
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Dear all,
I have a K75S I have taken apart to replace seals all the way to the main seal, lube the clutch spline, etc., and have the bike back together operating flawless and rather smooth ever since. Obviously I have planned somewhat ahead, so I did a few things at once, but guess what, I have never ridden the bike in the rain before (as I owned the bike for less than three months) and now the crappy weather just arrived. After my first properly rain soaked ride my gear indicator started to misbehave, I know, I will have to go in there again, remove the swingarm and seal the crap out of the switch (it is not crumbling to pieces, I have seen it's condition maybe a week and a half ago). I already managed to let go of the clutch once thinking I am in neutral, well, I was not, but fortunately I did not bang into a car in front of me doing that. But that made me think, does the bike get it's information regarding neutral from this very same switch? What I mean, can you start the bike without clutch in gear, because the bike thinks it is neutral? I was very cautious not to start the bike on the side stand even if it showed neutral and the N light glaring and I will get in there again very soon to dry and seal the switch but in the meantime I am scared, I will have a bike launching into orbit with the starter pushing the bike on...
Thanks!
Gabriel
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Gabriel, I feel your pain. Been there as well. Fortunately, the switch dries out enough to function after a day or so.
As far as sealing, be aware that you never know when you might have to go in there again, so you want to use something that can easily be removed. I seal mine with a self-amalgamating tape that sticks to itself without adhesive. It seals well and is easy to remove.
Another thing you want to do is get a good gasket between the switch and the transmission. You wil have to make your own because BMW no longer supplies it.
Have you serviced the switch? if not, do it and put a small amount of electrical grease in there to protect from corrosion.
Last, I am in the habit of holding the clutch when stopped, even in traffic. Pulling the clutch lets you start in gear, but you need to hold it in. Maybe you want to get in the habit of mounting the bike before you start the engine, so as soon as you start you are ready to drive off. You might want to do that when the indicator is misbehaving.
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Gabriel, I feel your pain. Been there as well. Fortunately, the switch dries out enough to function after a day or so.
As far as sealing, be aware that you never know when you might have to go in there again, so you want to use something that can easily be removed. I seal mine with a self-amalgamating tape that sticks to itself without adhesive. It seals well and is easy to remove.
Another thing you want to do is get a good gasket between the switch and the transmission. You wil have to make your own because BMW no longer supplies it.
Have you serviced the switch? if not, do it and put a small amount of electrical grease in there to protect from corrosion.
Last, I am in the habit of holding the clutch when stopped, even in traffic. Pulling the clutch lets you start in gear, but you need to hold it in. Maybe you want to get in the habit of mounting the bike before you start the engine, so as soon as you start you are ready to drive off. You might want to do that when the indicator is misbehaving.
Gryphon - I meant to use some black (or red) high temp RTV, so I can get it off anytime and if it seals my bathroom OK (well the sanitary version), it should seal the switch too (as it might not get a proper spray, but flowing water). Before this bike I rarely bothered with the centre stand, as they are always a pain, but on the K I put it on that all the time, as that saves me from embarrassment two hours later, when I return to the bike :) So even if the wheel spins, it is not a biggie, but I am sure, the srag gears and the starter motor are not particularly happy about driving the whole driveline...
I can make a gasket out of cardboard (I still have some of that child cereal box, but do not tell Jo that :) ) and smear it both sides with the RTV for good measure, I might also cover the whole shebang with RTV, it is cheap and saves me from the hassle of venturing in there again two weeks down the line. I have not touched the switch, as Chris Harris was quite clear to leave the f+cking f+ck alone (his words), but I will do so now. Is that switch bathed in gear oil? Do I need to drain the oil first to avoid spillage?
Also I do hold the clutch, if doing a short stop, if a traffic light is a long wait one I just pop the bike out of gear and stretch my sore back :) Many times I even kill the bike, although I am sure that saves me probably no petrol, or a minuscule amount :) Mounting the bike before start is a good idea in the summer, in the winter I like to leave my bikes to warm up a tad, so it gets a bit warmer before doing the first redline :) (I never do that, but still)
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Here is something like the stuff i used.
https://www.ebay.com/itm/Plymouth-USA-Plysil-20-Self-Fusing-Silicone-Rubber-Tape-1-x-020-x-30-Ft-MBD014b/253287011481?hash=item3af9151499:g:oMYAAOSwv0tVW1Cv
Much easier to remove than silicone sealant goop. You can also use it to insulate wires and seal hoses like the breather that causes idle roughness.
For the gasket, the cardboard is okay, but I would just grease it before I installed it. Also, replace the screws that hold the switch to the transmission with stainless Allen head screws. They will make installing and future removal much, much easier.
There isn't any oil behind the switch. What sucks is that you have to remove the battery tray to get the switch off of the bike.
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Here is something like the stuff i used.
https://www.ebay.com/itm/Plymouth-USA-Plysil-20-Self-Fusing-Silicone-Rubber-Tape-1-x-020-x-30-Ft-MBD014b/253287011481?hash=item3af9151499:g:oMYAAOSwv0tVW1Cv
Much easier to remove than silicone sealant goop. You can also use it to insulate wires and seal hoses like the breather that causes idle roughness.
For the gasket, the cardboard is okay, but I would just grease it before I installed it. Also, replace the screws that hold the switch to the transmission with stainless Allen head screws. They will make installing and future removal much, much easier.
There isn't any oil behind the switch. What sucks is that you have to remove the battery tray to get the switch off of the bike.
Great tips Gryphon, I did not even know, there is such a tape in existence :) I have planned to slide the swing arm wheel and everything else attached a couple of inches, but I guess if the tray has to come out, I might just do it properly. At least I will have a rough idea, how does the new trans output seal doing, even if it was only one full tank, since I have been in there :)) Given this issue and the amount of crap, I had to scrub of the arm and the rear of the trans, did. anybody install a fender extender? I know, the paralever models had that optional, but there is more space between the wheel and the trans, is it doable, or feasible to make one out of a bucket oe something?
Thank you,
Gabriel
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Look up http://www.motobrick.com/index.php/topic,7914.msg57755.html#msg57755
Regards Martin.
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Look up http://www.motobrick.com/index.php/topic,7914.msg57755.html#msg57755
Regards Martin.
Martin, thanks, that is exactly the thread, I have taken the bucket idea from, but does that apply to the rear fender's front portion too?
Thanks!
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I put an extender on my 16V K100, and probably should do the same on my K75's since Ilsa, the RT, occasionally has gear indicator issues when riding in heavy rain.
There is no extender that I know of for the K75 rear mudguard so I will probably do the old standby of cutting one out of an old inner tube and pop riveting it to the existing mudguard. Because of the space it needs to fit in, this may be the easiest solution.
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I put an extender on my 16V K100, and probably should do the same on my K75's since Ilsa, the RT, occasionally has gear indicator issues when riding in heavy rain.
There is no extender that I know of for the K75 rear mudguard so I will probably do the old standby of cutting one out of an old inner tube and pop riveting it to the existing mudguard. Because of the space it needs to fit in, this may be the easiest solution.
Yes, that sounds like a plan. Although the tube will have to have a 90 degree bend in, unless you pop it to the downward section. My scooter had a similar solution albeit coming from the factory, a rubbery sheet was covering the 'front' section, where the rear wheel would have spluttered crap all over the engine, the bottom part of the sheet was cut into ribbons I guess to prevent the wheel catching the whole sheet or maybe to lie flat on the various bumps of the engine bay
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Just keep in mind that the purpose of the flap is to protect the switch from spray.
It doesn't have to be attached to the mudguard. It could come over the top of the transmission and fit between the swingarm and transmission. Inner tube should be flexible enough to be tucked anywhere it is needed.
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I have had good luck sealing them up with RTV silicone but the tape seems like it is a better idea.
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Just keep in mind that the purpose of the flap is to protect the switch from spray.
It doesn't have to be attached to the mudguard. It could come over the top of the transmission and fit between the swingarm and transmission. Inner tube should be flexible enough to be tucked anywhere it is needed.
That is true. Although I might try to protect the whole back of the transmission, as the clutch arm was so caked in sh*t, it barely moved, no wonder, one needed superman powers to operate it also the various crevices were choc-a-bloc with the same crap, so if they meant to cool the bike anyhow, they certainly did not do that :)
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The same method can be applied to making a rear mudflap. You will need a heat gun and round bar ( the diameter is determined by the curve needed) to form the bends over, gloves (thick), scissors and cardboard. Make one out of cardboard first and once you are happy with it transfer the dimensions to a square bucket. Cut out the pattern out of the bucket allowing about 1/4 to 1/2" excess. Clamp the round bar in a vice and gently heat the plastic on the line of the bend and form the bend over the round bar with your hands (gloved). Go slowly heating and bending until you have the correct angle then do the other side. Play with a bit of scrap to determine how much heat is required.
Then second bend requires more patience and you need to frequently check so the it fit right. Once correct do the final trim and polish. There are a couple of ways to mount it and you will need to determine which way you are going to mount it before you make it. You can slide it under the original one and screw through both. Or you can butt it up to the original and use an aluminium strip with a double row of holes and screws, or glue a plastic strip to the back of the new flap and use a single row of holes and screws.
Regards Martin.
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OK, so I have not had time to address this till now, most probably the weekend will see me sorting out the switch and the fender extender, thanks for the tips.
To answer my own question, yes, the bike will want to start even if in gear if the indicator is misbehaving. I am not sure, where the signal stops the starter to engage, most likely there is a loop from the cluster, so if you are fooled, the bike is too. Today I had the bike on centre stand and I was suspecting, I am in gear, although the indicator showed zero (the neutral light was not on) and guess what, the starter started the bike without clutch and spun the wheel. Whilst this is dangerous, if the bike is on the side stand or in one's hand it also most likely puts an excessive stress on the starter motor, as it turns the whole driveline, not just the crankshaft.
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Fitting a grease nipple to the clutch pivot arm is recommended. An occasional shot of grease stops the ingress of water and road crap and eases operation.
Regards Martin.
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