Polishing a "Naked" K75: From Storage to Tourage

[technostructural]

I introduced myself on the Front Porch, and as mentioned, I am going to chronicle the process of getting this K75 ready for a riding this summer.

The jist of it: This is my uncles bike that has been sitting for over a year and half. It fired up without any issues (only needing a battery boost). This isn't a thread where you'll see someone rebuild a K bike from disaster to show-room perfection. There will be no sexy cafe styling and uber amounts of money spent making sure I have the correct BMW badge to go on my freshly painted tank -- this is a thread drafted by someone who has been a student for almost 10 years, and is looking to finally let loose after graduation; and on a budget.

I am incredibly thankful for all of your expertise and words of encouragement so far - I hope you're willing to continue.

To kick things off, here are a few photos of the bike, whom I have not yet named. Her name is "Schatz" (a German word of endearment, meaning "treasure", which also sounds good to exclaim when things don't go well, e.g., "Ahhh Schatz - the fuel pump went again?")

She had been sitting for about a year and a half when I fired her up today. There was a bit of smoke, and she didn't want much throttle at first; but after an hour or so, she was ready for the open road (kind of).

[Chaos]

hey, you got it running, that a big deal :2thumbup:  Nice pinstriping!

[Gio]

Congratulations on start-up! For some reason I thought your bike had been in multi-year storage, so am not too surprised to hear yours starting up after only a year ... whilst in the UK mine would often go for a year or so with only a trickle-charger for company - and always started easily.

The knocking sound you describe could just be expansion as the engine warms up (?) - if it goes away when up to temperature then I wouldn't worry.

I would treat with fuel injector cleaner (no need for name brand - regular stuff from CT is fine - I give my bikes a shot at each oil change), run this through with the old gas and then top-up with fresh premium/Stabil if (presumably) going back into storage for a while.

Good luck with the project - and enjoy!

Gio

PS - I notice you have the low-seat. I have a complete standard (high) seat kit FS (incl black panels) if interested.

[Bokobob]

Might want to check the age of the tires..if older than X years (you supply your own number.  I would say no more than five years old) it might well be prudent to put on new ones..also, some don't like it, but for a long trip it would seem prudent to me to take along a tire sealant..RideOn is much friendlier than Slime in the clean up aspect...

Have fun.

[technostructural]

Might want to check the age of the tires..if older than X years (you supply your own number.  I would say no more than five years old) it might well be prudent to put on new ones..also, some don't like it, but for a long trip it would seem prudent to me to take along a tire sealant..RideOn is much friendlier than Slime in the clean up aspect...

Have fun.

Thanks Bokobob,

I'm actually quite lucky in that the bike had been given a fresh set of tires in 2012. I will definitely be taking tire sealant with me!

Edit: Oh, and my uncle was kind enough to dig up an old email exchange with the previous owner. This is his report of the maintenance log:

EXISTING CONDITION:
 
Approximately 108,000 km (these engines & drive trains are good for 200,000 - 300,000 km like a car)
Cosmetic imperfections
New Parts/Service since owned:
 
Headlight Bulb (2011)
Oil & Filter Changed (2011)
Tires (2009) - Good condition
Shaft (2009)
Front fork seals (2009)
Coolant (2009)
Brake fluid (2009)
Fuel filter (2009)
Air filter (2009)
Spark Plugs (2009)
Headlight switch (2005)
 

I purchased it in 2004 with 86,000km and am the third owner.
Reason for sale: purchasing another motorcycle.

I know also that, before sitting, it had the following done:

(1) splines lubed
(2) "new" rear suspension (should we say "gently used"?)
(3) fluids were flushed and replaced
(4) new tires


So, all in all, I suppose things could be a lot worse in terms of neglect.

More to come soon!

[pdg]

If the tyres are good, then IMO age is irrelevant - BUT, if you're going to be doing a big miles trip and the tyres are a bit worn, it would make sense to bung a new pair on. It's a pain to be stopping for new tyres half way through a nice trip - if the 'old' ones are still good, keep them and use them later.

As for tyre sealant goop - I would heartliy recommend you never stick this evil creation in your tyres. Again, there's a 'but'... If you have some in your bag and get a flat many miles away from anywhere you know, it's much less hassle to plug up the hole with some goop and then find a repair place, so much better than sitting by the side of some unknown road waiting for help to (possibly) turn up.

[technostructural]

So, I took a few minutes today to wipe her down and take a look at what I'm working with. All in all, things look pretty good.



However, it looks like one of the breather hoses/air intake boots may have a leak?



There is also a small hose that seems to be past its prime here:



Any thoughts? I am not as familiar as this engine as you all are, but this to me looks like maybe a crankcase breather valve is broken? ("PCV valve") This happened on my VW Golf, and I had this oily crap all over the air intake.

I'm going to bust out the service manual and see what this might be, but any thoughts are welcomed!

[Elipten]

Common issue of that hose cracks and has that oil issue.  It is the crank case breather hose.  Not expensive from BMW and easy replacement.  I would pull the chamber above the throttle bodies as no doubt has some oil film or oil in it.  Cut the clamps and replace with screw type clamps.  There was just a posting on which clamps to use.   PM me and I can send the part numbers

[technostructural]

So, I siphoned the gas out of the tank, and replaced with just a couple litres of fresh stuff. I didn't want to put too much in it because I will be eventually taking the tank off to clean it up and repair a small paint blister and likely spot of corrosion on the lower-left side. Oddly, it doesn't seem to be leaking yet, but I want to nip it at the bud.

On that issue, I have a question that I haven't yet found the answer to -- when doing the JB Weld / Permatex patch on the gas tank, is it preferable to make that repair from the inside or outside of the tank? From what I can tell, it seems pretty hard to get in there from the inside on that lower lip.

I also changed the oil yesterday, and I was happy to find an OEM filter. I'm just hoping it's not the original!  :hehehe

While cleaning out the trunk, I found a few goodies as well, such as:

(1) Oil filter wrench:



(2) Tool kit!



(3) Odds and ends:



(4) CO2 cartridges??? - anyone have any idea what these would be for?




From what I can tell, the previous-previous owner was/is a pretty meticulous guy and took good care of things. From what I've been able to see so far, I don't see any half-assed silicone jobs, or RTV sealant holding things together. Looks like quality OEM parts have been used.

My next project will be replacing the coolant and brake fluid, and testing the radiator fan - as I think it might be faulty. This leaves me with two questions:

(1) the coolant "sight" tube, on the side of the overflow tank. Is there a relatively easy way to replace this using some high-heat tubing and hose clamps? I thought I remember seeing someone do this. Mine is milky, and I can't see a damn thing through it. I would replace it with OEM, but I'm not able to find that anywhere online, despite a number of people saying that it's "an easy fix".

What is the usual fix for the sight glass on the coolant reservoir? I remembered that the fix with the "tube" was only on other K bikes, I think maybe the K100? My sight glass is opaque - I haven't been able to find this part on Bob's BMW or Beemerboneyard. Does anyone have a part number?

(2) testing the radiator fan - Is there any easy way to do this? I know on my old VW Golf, if you turned on the ignition to give current to the electronics, you could bridge two of the prongs in the radiator's wiring clip that would make it fire up. This was an easy way to test it. Any similar approach here?

Thanks all.

[The Mighty Gryphon]

I am loving that pinstriping on the tank.  Very "classic R bike" looking. 

The CO2 cartridges are used with that brownish tube in the picture of the spare doodads to inflate a tire after you do a roadside repair.

Regarding the sight tube in the overflow tank, I would think a piece of clear vinyl tube from the hardware store should work.  No need to pay $6.42 for the BMW part.  Alternatively, they are several complete tanks on eBay at any given point in time. 

Regarding eBay, searches for "BMW K75" and "BMW K100" will bring up a plethora of used parts at prices ranging from very reasonable to even more expensive than new at the dealer.  You will also want to get familiar with the parts fiches at Max BMW.  Once you get used to them you can use them to get part numbers and check part compatibility between various models.  Max BMW is also a great place to order parts. 

http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51741&rnd=04282014

You can check the fan by manually spinning.  If it spins easily, the bearings are probably OK.  To do an electrical function check I would get a piece of wire about a foot long and strip about 1/2" at each end.  The temperature control relay has a pair of terminals that go to contacts that energize the fan.  I can't tell you off the top of my head which terminals they are, but if you do some searching you should be able to find out where the relay is and there should be a contact diagram on the case that tells you what terminal is what.  Jumping the contact terminals on the relay socket should make the fan run when the ignition is turned on.

[technostructural]

I am loving that pinstriping on the tank.  Very "classic R bike" looking. 

The CO2 cartridges are used with that brownish tube in the picture of the spare doodads to inflate a tire after you do a roadside repair.

Regarding the sight tube in the overflow tank, I would think a piece of clear vinyl tube from the hardware store should work.  No need to pay $6.42 for the BMW part.  Alternatively, they are several complete tanks on eBay at any given point in time. 

Regarding eBay, searches for "BMW K75" and "BMW K100" will bring up a plethora of used parts at prices ranging from very reasonable to even more expensive than new at the dealer.  You will also want to get familiar with the parts fiches at Max BMW.  Once you get used to them you can use them to get part numbers and check part compatibility between various models.  Max BMW is also a great place to order parts. 

http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51741&rnd=04282014

You can check the fan by manually spinning.  If it spins easily, the bearings are probably OK.  To do an electrical function check I would get a piece of wire about a foot long and strip about 1/2" at each end.  The temperature control relay has a pair of terminals that go to contacts that energize the fan.  I can't tell you off the top of my head which terminals they are, but if you do some searching you should be able to find out where the relay is and there should be a contact diagram on the case that tells you what terminal is what.  Jumping the contact terminals on the relay socket should make the fan run when the ignition is turned on.

Thanks Gryphon,

I really like the pinstripe too. It gives it a classic look - which I am definitely a fan of.

I looked into the coolant sight tube, and (I could be wrong) it seems like there are two variants. One style is an actual tube, and the other is sort of a bubble, or "glass". My coolant reservoir is like this one:



The part listed on MAXBMW is actually a separate tube, that looks like it would be way easier to rig up a replacement yourself. I wonder if there is a replacement part for this plastic window style sight tube? I have yet to see one.

Thanks for the heads up about testing the radiator fan too. I found this really good guide for testing it, in case anyone is reading this thread and is curious about the same thing: http://www.ibmwr.org/ktech/fan-diagnosis.shtml

Cheers.

[The Mighty Gryphon]

Here's an old style tank on eBay with a replaceable tube. 

http://www.ebay.com/itm/1985-BMW-K100RT-K100-K-100-RT-100RT-1000-RADIATOR-RESERVOIR-TANK-/400371748017?pt=Motorcycles_Parts_Accessories&hash=item5d38040cb1&vxp=mtr

I had a similar problem with the tank on my K100.  There was a lot of crud in the tank from crappy water a previous owner must have used.  I filled it with white vinegar and let it sit for a couple days and rinsed it out.  Made a big difference.  You might have to do this a couple times. 

If such is the case, you might want to add a cooling system flush to your list of things to do.  Distilled water is the thing to mix with your antifreeze.   

[technostructural]

So, I changed the fuel filter today.

I replaced an OEM filter with a NAPA Gold 3032 (recommended by you folks).

I figured I would snap a shot of the two filters side-by-side for reference. I read somewhere that the NAPA filter has a lower bursting point -- which I suppose would be an issue if it were likely to burst. Given the amount of people using the NAPA filters, I figure that something would have been reported by now if it were a real issue.



I cleaned out the tank as best as I could while I had everything open. There was a sort of fine dust all throughout the tank which was hard to detect until you wiped it with a clean rag.

In any event, it's better now than it was!

I also took the rear wheel off and inspected the drum brakes. All in all, I think they look pretty good and should be fine once cleaned up.





Thanks for reading.

[johnny]

greetings...

the napa filter is a little smaller than oem... i have had them clog up while riding...

now i install a new one every 10 thou miles... been 100% since...

j o

[technostructural]

Hello All,

After a few days in Florida, I'm back at it.

I lucked out, and scored an awesome deal on some saddlebags. More photos and updates on that coming soon.

In the meantime, I'm curious to hear what you guys think of this blister on my gas tank. It looks like the classic corrosion that is usually fixed with Permatex/JB Weld, but the odd part is that it is not leaking:





I figured I would sand it out and do the JB Weld fix (I bought some "water weld" which is apparently suitable for gas tanks). I just find it odd that it may be corroded but not leaking. Is this possible if a blister is showing on the outside?

Also, I haven't yet found any good descriptions of how people do this repair. Has anyone found a good guide or DIY?

Cheers.

[xians421]

So THAT'S what that lower left indicator does. Thanks.

[Fossil]

It looks like a leak in the making. Fix it with  a 'Caswell' sealant product. It's a two part epoxy type stuff and seals tank on the inside. Goggle it.

[fourwinds]

The Caswell tank sealer is a wonderful product.  Easy to use, great results.

[technostructural]

Hello all,

So it's been a little while since I've got much work done on this project, but it turns out that I'm scheduled to take off in less than a week. So, I've been busy.

I decided to go ahead with making the repair to the gas tank. I didn't catch pictures of my prep work (prior to JB "waterweld"), but I did snap a few photos throughout the process:







Oh, yeah, apparently there was this book that people use to use to find telephone numbers. In previous civilizations, this giant, cumbersome book had to be republished yearly. I figured it'd be better off used as masking for painting. Especially the "government services" section.



I know you're probably thinking that it will end up looking horrible with the tape lines, but it's actually so low on the tank that you don't even notice it. The line is in conformity with the shape of the tank, so it kind of works visually. I'll get some more photos when it's on the bike later on.

I also took the time to get the radiator fan fixed. I followed the advice of other motobrickers and went ahead with the Spal Puller fan mod:



That's all for now!

Tomorrow I will be putting the radiator back on and replacing the coolant, and hopefully bleeding the brakes. My bike only has disc brakes in the front, and there is no ABS. This should make it relatively easy. The repair manual says that I need a special tool to retract the piston. Any comments on this? I have yet to find a thorough DIY for bleeding the brakes on these bikes.

Cheers.

[technostructural]

Radiator is back in, and brakes have been cleaned up and bled. A little bit of brake clean, sandpaper and synthetic lubricant can go a long way in breathing some life into old brakes!

The fluid that came out of the two callipers looked like coffee. Definitely time for a change.

I am also very, very pleased to show off these new tragkorbs that I picked up. I bought them from Motobricker mw074. He has other sets available if you're looking, and very reasonable prices. He ships from Michigan, and is a very friendly guy. He gave me a ton of tips about riding/repairing my K75 in general. Much appreciated. Anyway, here is a photo of the tragkorbs. Not too shabby! Thanks mw074!

[technostructural]

So, today I started on the spline lube. The four bolts holding the final drive on were a total pain in the ass to get off. I thought I was going to break an 8mm allen key in half. With plenty of cursing, I managed to get them out and took a look at the rear splines. I was happy to see that they were at least not dry:





Once I cleaned them up, I have to say I am pretty happy to say that there is minimal wear. The shaft shows a tad bit more than the drive. I've seen a few videos/photos of these, and based on those comparisons, I think I am in pretty good shape here. After 110,000km, or 68,350 miles - not to shabby:







I didn't have a brush suitable for lubing them, so that part will start tomorrow. I am going to use Honda Moly, because it is the easiest and most affordable thing around for me. I'll also be changing the final drive and transmission oil. In the meantime, this war zone of a place has been my mad workshop for the past few days:



Thanks for reading.

[billday]

Thanks for taking time to post. Hope the gas tank repair works out.

Where are you riding to when you get it all together?

[technostructural]

Thanks for taking time to post. Hope the gas tank repair works out.

Where are you riding to when you get it all together?

Hi billday,

My original planned route was quite long, but.. a number of things have come up since planning it, and this will be my first relatively long ride with the exception of a short camping trip with my girlfriend on my Suzuki GS450 two years ago.

I'll be taking 4-5 days to do the Cabot Trail in Nova Scotia.

Cheers.

[Elipten]

Splines look good. Use antiseeze when reassemble