Post by: Kt88 on November 22, 2023, 10:42:09 AM
I’d just sold my 71 r75/5 after bringing it back from a circa 1980 slumber, having ridden it around for a year or so.
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Lo and behold, delivered to my eyes was my next obsession: a derelict k75 down in the Florida Keys.
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Now, other life occurrences meant I have a shoestring budget (good for a derelict k75), no truck (bad for a derelict k75), and about a day to make this all come together. Compounding my sense of urgency, this bike was priced as if it weren’t in South Florida, where there’s got to be some rust tax that adds 1k to every asking price for some reason I’ve yet to fathom.
So the plan, as dumb as it is, is to go down and rouse the machine and.. ride it back. It’s only 80 miles, what could go wrong?
My better half and pup go down with me and my trunk of tools. Upon arrival, I recognize that pictures were kind, and salt air isn’t. Everything is crusty and rubber is a flimsy concept rather than a pliable material. If it were easy, though, it’d not be an adventure, right? ..at least that’s what I told my wife as she watched this calamity unfold.
All told, major items that were kaput:
Fuel pump and filter (expected)
Sending unit (was hoping it wouldn’t have lost continuity but.. darn)
Front master cylinder (frozen dry and filled with powder)
Front tire (valve stem rotten)
Rear shock frozen upon first compression
All keyed cylinders frozen (one key only, better be gentle)
New battery, drained and flushed tank, but old fuel pump was unsalvageable. The auto parts stores down in the keys could get a Bosch pump that crossed over part numbers, but they.. forgot to put it on the truck when I ordered it. I cobbled together a pump, sock, and wiring from a Chevy application that had similar gph ratings and was on hand- I’ll go stock once I have parts in hand. The sender unit solder had let go, so for the moment, I am powering the pump from the four pin connector to wires coming in through the gas cap. Very classy!
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Once the pump was pumping upon turnover, I verified we had spark (strong), and cranked. No dice yet. Pulled the fuel rail, sprayed off the ends of the injectors, then reassembled to a bunch of new little rail leaks from old o-rings. A couple washers on the rail to increase the pressure on the o-rings later, we have seals, and magically, we have engine life.
The rear brake bled out well, relatively speaking. The front MC will need complete rehab- at this point, it’s Sir Not Appearing In This Film. However, it’s worth noting that after a year of r75/5 riding, my braking distances mentally are measured in half miles anyway.
The front tire isn’t holding pressure. Upon examination, the valve stem is leaky around the seal. I’ll clearly get new tires, but to get home I use self sealing silicone tape around the stem. Probably one of the most willfully moronic things I’ve ever done, and surely I won’t repeat that choice.
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I replaced all the fuel lines, the overflow reservoir line, and hit the magic button. Off we went. Wife following me, we took our sweet time and turned an 80 mile trip into a 2.5 hour amble (then again, the Keys are generally 45 mph, so it wouldn’t have been terribly different under normal circumstances, either)
After exactly no real drama, other than some fueling misbehavior at the very end of the ride after an hour of freeway, the bike is in its new home, safe and sound. And the process of correcting hack mechanic work and the ravages of time begins.
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Now for the fun: disconnecting the 90s era alarm system (titan 3003), identifying another clear PCB accessory wired in with no brand name of any kind, returning stock functionality in all systems, and cosmetically freshening the bike up.
I’m not into modifying bikes these days- I’ll keep it stock as appropriate, with possible suspension upgrades.
One note, and maybe I’m preaching to the choir:
Coming from airheads (I’ve had about 35 or so), I’ve always been told a k75 is a great engined bike, but has no character. Riding back under very far from ideal circumstances last night, I didn’t feel that way at all. I would have screamed for joy for my R bikes to run as smoothly as this abandoned k75 did last night. I would have started threads on ADV detailing how I got there. I’d have written novels about the smooth tractability of the power. Do people just not like the K architecture as much? The frame felt great, and I had NO rear suspension. I can only imagine how much more I’ll love it with actual function. Is this me having rose colored glasses on because I moved from a bike built in 71 to one built in 91?
Anyway. I’m currently in love and can’t wait to make the bike fully functional, safe, and a daily again.
Post by: Chaos on November 22, 2023, 01:59:20 PM
Post by: Kt88 on November 22, 2023, 02:12:39 PM
Replace front valve stem
(Maybe) boil front master cylinder to try and free it up?
(If there’s time) take rear shock off to see if I can make it, I dunno, move at all?
(Definitely not today, maybe tomorrow) go get new injector o-rings so I can stop using extra washers to seal the rail- as the extra washers that were on hand were in fact actually cabinet corner hardware and not even kind of inconspicuous.
Post by: The Mighty Gryphon on November 22, 2023, 06:11:51 PM
I think the problem with the Bricks is that the traditionalist airhead/boxer fans have spent nearly 40 years bad-mouthing them. I have found mine to be super reliable, bulletproof and capable of running 85+mph smoothly for as many 800 mile days as I could handle. They are great Iron Butt machines. I have easily kept up with and even pushed guys riding 1000 and 1200cc machines on the interstate as well as the mountains.
They are cheap for what you get, easy to work on, and parts are still easy and not too expensive to find.
Post by: Kt88 on November 22, 2023, 08:29:49 PM
I think there’s also some aversion amongst the airhead-only guys to really rev these. Despite being told for years that my type 247s could live just fine at 5k+, I tended to still cruise around 4500. So for the most part the enjoyable bit of the engine was low speed torque.
Now keep in mind 90% of my riding with this is with a flat front tire (sweet lord I’m a moron), but my feeling is this will take mildly more clutch work and much more revs to find the happiest point for the drivetrain. I’m fine with that. I think I’ve definitely put enough time in on the R twins to have a good idea about the attractive parts to those bikes, and I’m mostly excited to figure out new things to love about these.
Now to check on the tire, suspended above a boiling master cylinder- hopefully it will become pliable enough to seat the bead with a ratchet strap and foot pump, as that’s what I’ve got.
Post by: Laitch on November 22, 2023, 10:26:16 PM
Coming from airheads (I’ve had about 35 or so), I’ve always been told a k75 is a great engined bike, but has no character. Riding back under very far from ideal circumstances last night, I didn’t feel that way at all. I would have screamed for joy for my R bikes to run as smoothly as this abandoned k75 did last night. I would have started threads on ADV detailing how I got there. I’d have written novels about the smooth tractability of the power. Do people just not like the K architecture as much? The frame felt great, and I had NO rear suspension. I can only imagine how much more I’ll love it with actual function. Is this me having rose colored glasses on because I moved from a bike built in 71 to one built in 91?Sounds like you're in the honeymoon phase. Keep up with the candy and flowers. :laughing4-giggles:
Good luck with your Brick.
Post by: The Mighty Gryphon on November 22, 2023, 10:45:50 PM
Have you ever tried putting a little propane or starting ether in the tire and lighting it off with a bunch of soapy water on the beads? Boom.
The 75 has a pretty decent power band with usable torque from about 2500rpm for city riding. When I first got mine, I was constantly fishing around for 6th gear. Then, after a year and 10,000 miles I found myself riding on the interstate at 65-70 in 4th gear. The classic K engine loves to rev. I have heard that it has been tested running at redline under full load for 24 hours. That translates to around 2700 miles in one day. I know that I was able to do 1500 miles in one day on a fully loaded K75RT that had 85,000 miles on it.
Post by: caveman on November 23, 2023, 06:50:45 AM
I got my 75s just to go on day rides. I felt like a moron riding a touring bike for a day or weekend ride. Long story short it is my go to outfit and has bin cross country several times. Please keep us posted on the progress with your bike.
Post by: Laitch on November 23, 2023, 09:22:19 AM
Have you ever tried putting a little propane or starting ether in the tire and lighting it off with a bunch of soapy water on the beads? Boom.Here's an educational video with a compelling soundtrack to clarify the process, Kt.https://www.youtube.com/watch?v=9WwUwZ0Fvro (https://www.youtube.com/watch?v=9WwUwZ0Fvro)
Post by: Kt88 on November 23, 2023, 11:57:48 AM
Here's an educational video with a compelling soundtrack to clarify the process, Kt.https://www.youtube.com/watch?v=9WwUwZ0Fvro (https://www.youtube.com/watch?v=9WwUwZ0Fvro)
So you’re telling me I shouldn’t use a tractor/trailer rim setup? Pretty disappointed in that news.
In a previous life I was a tire tech (ah, the early 20s) and I still never did the old farmer’s trick of exploding a tire onto a rim. Working out of a big shared apartment garage I’ll probably try to keep the explosions inside the cylinder walls and wait until someone with a compressor is open around me , and try to seat it the old fashioned way. I’m only keeping this tire on long enough to have new ones mounted at a buddy’s shop- but that’s an hour and a half north of here.
In other news, three hours of boiling the master cylinder did.. nothing at all. So I’ll be sourcing a replacement, which is probably a better bet anyway.
In better news, the bike fires immediately on the center stand right now, no hesitation. That’s promising.
The water temp indicator is still illuminating while running, but I’ve not traced that circuit at all.
Shopping list as of now (to be executed once there’s budget for it):
Front MC
Rear Shock
Sending unit (tempted by the 17$ two wire one I saw another inmate post about, even if it’s temporary)
Injector seals
Then just work through the rubber bits little by little.
When I have the rear wheel off for the new tire I’ll do my due diligence on the splines. I don’t think pulling this transmission looks any harder than an airhead transmission.
Post by: frankenduck on November 23, 2023, 12:11:11 PM
Metal valve stems: BikeMaster 151402
The K75's "character" is all above 4,500+ RPM. Run through the full range up to the rev limiter at 8,700 RPM. You'll have peak torque a little under 7,000 RPM. (Bouncing off of the rev limiter won't hurt it.)
Post by: Kt88 on November 23, 2023, 01:47:50 PM
Send the injectors to: https://www.mrinjector.us/
Metal valve stems: BikeMaster 151402
The K75's "character" is all above 4,500+ RPM. Run through the full range up to the rev limiter at 8,700 RPM. You'll have peak torque a little under 7,000 RPM. (Bouncing off of the rev limiter won't hurt it.)
New valve stem in, just ancient rock hard rubber trying to bead seat with a foot pump isn’t likely.
Duck, to be honest, when building the fascination for the k75 in my head I ran across about a thousand posts of yours on ADV and they probably have a lot to do with pushing me over the edge to the point of purchase. Thanks for that!
Post by: frankenduck on November 23, 2023, 02:56:16 PM
And a bunch more K bike stuff: http://bit.ly/kbikemandm
Post by: Kt88 on November 25, 2023, 12:18:45 PM
Front wheel is back on with the old rubber, just waiting until I can get fresh tires to put on it.
My luck may have run out with my for-retrieval-only fuel delivery situation. The bike will start but won’t take throttle at all, but I’m not actually upset at that. It’s time to dump all fluids and change all filters anyway, and the pump situation in the tank was always meant to be temporary. If anything, this will force me to get the rest of the braking situation settled before I get carried away with test rides.
After a few days of penetrant soaking the bag locks are finally behaving like they should. Key is turning easier in ignition also. It’s almost like the bike really wants to be alive!
Post by: ErikDK on November 26, 2023, 11:50:37 AM
A hi/lo lever like the Honda CB750 C would be awesome on the K75, or even better an electric operated under/overdrive
Post by: Kt88 on November 28, 2023, 10:31:32 PM
The front master cylinder, while freely moving, is not holding pressure- or even generating it, for that matter, just bubbles- so I’m now shopping for one in usable shape or at the minimum worthy of a rebuild kit.
I’ve started replacing bulbs to get the bulb indicator light to relax a little upon startup. Those connections still seem pretty intact, but the PO’s alarm system is tied into almost every single part, including all the marker/blinkers. I’m a bit hesitant to just start pulling it since I imagine it’s protected against that method somehow, but I will absolutely do it before any big miles.
Once the front brakes are happy, then it’s time for new tires- open to recommendations there- full spline service, and flushing all fluids stem to stern.
Oh, and the plastic fairing support is cracked all the way through. It’s held together with tape at the moment. I’ll replace that, too.
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Post by: frankenduck on November 29, 2023, 01:20:12 PM
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/radials/radials.htm
Post by: Kt88 on November 29, 2023, 02:37:14 PM
Post by: stokester on November 29, 2023, 05:13:26 PM
I like riding my Airheads and K75s as they both have their own character.
You've come to the right place for information and recommendations.
Keep us updated on your progress.
Nick
Post by: Kt88 on December 03, 2023, 12:56:56 AM
I’ve read a lot of threads about flickering or worry that the light doesn’t illuminate at all, but it’s been solidly on since the engine ran for the first time in my possession. If the key is on, the light is on.
Figured I’d ask the brain trust here- it seems to me that if the sensor wasn’t functioning at all or was always in low resistance mode, I’d have light on/fan on constantly. The fan seemingly operating as it should is interesting. There’s always the possibility that the temp light has been futzed with and incorporated into the alarm system (non op, thankfully) and it’s representing that now, but I’d hope not.
Post by: The Mighty Gryphon on December 03, 2023, 07:09:11 AM
First thing I would do is pull the temperature module and see if the light goes out. If the light stays on, the problem may be in the instrument cluster. If it goes out I would suspect the temperature module. Next thing would be to see if you can get a module to swap with the one on the bike for a positive test.
Post by: frankenduck on December 04, 2023, 03:03:42 PM
If everything temperature related is working properly, ie. the fan cycles properly, the cooling system isn't overheating and the engine isn't running on a bad mixture, then I would think the problem is in the temperature module, the instrument cluster, or possibly a wire with worn insulation shorting to a bare spot on the frame.
First thing I would do is pull the temperature module and see if the light goes out. If the light stays on, the problem may be in the instrument cluster. If it goes out I would suspect the temperature module. Next thing would be to see if you can get a module to swap with the one on the bike for a positive test.
Yeah, if it's running well and fan cycles as it should with the temp idiot light always on then I'd also suspect something funky with the thermo relay. (The white one on the right side of the relay box.)
Another possible cause for the temp idiot always on is that the VIO/BLK wire from the temp relay (Pin A3) is shorting to ground somewhere between the temp relay and cluster.
When you have the temp relay pulled the idiot light should come on if you ground the socket terminal for the A3 pin - with ignition turned on. (Pin layout is shown on the temp relay.)
Post by: Kt88 on December 13, 2023, 01:33:09 AM
I also got my Mr. Injector kit in and refreshed the injectors and got the fuel rail seated happily. Bike is purring like a kitten.
Replaced bulbs out of their economy and to lay eyes on all the sockets. For the most part healthy, minus some dessicated o rings that seal up the socket areas in the fairing. I’ll replace those too.
At this point I have a few tasks ahead to feel great about the bike altogether:
Change rear pads
Change tires
Fork seals/general internal condition inspection
Rebuild works rear shock
Refresh engine cosmetics
Fit belly pan (previous owner found it after swearing he’d never seen it in his life)
Flush fluids and investigate splines, various bearings
Repair or replace central fairing support
Find source of bulb monitor light warning
Find source of temp warning
Clean up existing paintwork and refresh frame and control cosmetics
Replace control cables
Finally-
Ride it a whole lot
Enjoying the heck out of this whole process! Thanks for all the info and support. Once I’m not working in a dark corner of a parking garage I’ll share some progress pictures.
Post by: Kt88 on December 21, 2023, 08:23:03 PM
Nevertheless, I’m persisting. It’s awfully rough on me, as you can probably tell.
Tags came in yesterday, and using the bike as my primary transport is now underway officially.
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I’ve got some more cosmetic cleanup to do on the old headlight glass (yellowed and foggy), the fairing attachment, and the glazed windshield. I may use this to justify buying a random orbital buffer.
Post by: Laitch on December 21, 2023, 11:16:42 PM
One of the nicer bits about living in Miami is that I essentially have year-round riding.Riding through summer afternoon squalls from the Big Cypress rolling over South Dixie Highway in Kendall while dodging flying palm fronds, broken tree limbs and assorted leaf litter was especially nice. :laughing4-giggles:
Post by: Kt88 on December 22, 2023, 01:09:32 AM
Riding through summer afternoon squalls from the Big Cypress rolling over South Dixie Highway in Kendall while dodging flying palm fronds, broken tree limbs and assorted leaf litter was especially nice. :laughing4-giggles:
I mean, with the radials and works shock I should be nimble enough, right?
Have to admit I prefer the gusty rain to blizzards and black ice, but I do miss the memory of vertical elevation or wandering, woodland narrows.
Post by: Laitch on December 22, 2023, 09:12:39 AM
I mean, with the radials and works shock I should be nimble enough, right?Couldn't say, Kt. I'd be riding on bias-plies, a YSS and infusions of café cubano. 112350
Post by: Kt88 on December 29, 2023, 10:52:27 AM
Some of the last truly broken things on the bike are in this part: the plastic that goes between the steering stem and the fairing that you can see while riding (I suppose it’s upper fairing mount, but I’m not having luck finding images of it; I’ll find the part number on realOEM for specificity’s sake), the headlight reflector and adjustor, the horn, and now that I’ve removed the miles of alarm wiring, the side marker running lights. I don’t anticipate it being difficult to make the running lights work again- they do work as blinkers still. Just have to tell the second filament to work on key on. The hazard switch is still non functional but I don’t particularly care.
Now the headlight: I may depart from my typical stock-is-best here. Reversibly, of course, but I’ve always been a huge fan of the mid 80s twin headlight muscle bike look and am tempted to put two 3.5” lights in the nacelle with an adjuster surround that mounts in the stock attachments if I can fit them. If I can’t, well, back to the stock I go, of course, just with healthy a reflector and adjustor knobs. I’ve not seen anyone else do that for this bike, so perhaps I’m overestimating the available area in the nacelle. I did this on an old Guzzi Quota I had and it made me love the aesthetic of the bike quite a bit more, but that lighting was dodgy from the factory anyway so there was also no functionality lost.
While I had the bike mostly naked I placed a few rubber strips under the gauge pod to combat the excessive bouncing while retaining some shock absorption ability. We’ll see how that holds up, but the brief reassembly test ride was promising.
Every wire junction I touched and all relays got a healthy dose of DeOxit while I was in there, but thankfully they mostly looked untouched by the hands of time. Thanks, wire connection manufacturers.
Post by: Chaos on December 29, 2023, 12:44:49 PM
Post by: frankenduck on December 29, 2023, 09:44:32 PM
Now the headlight: I may depart from my typical stock-is-best here.
The headlight used on the K75S is horrible at actually putting lighting on the road. The other Ks have decent headlights but the S headlight ducks.
Post by: Kt88 on December 29, 2023, 10:16:40 PM
The headlight used on the K75S is horrible at actually putting lighting on the road. The other Ks have decent headlights but the S headlight ducks.
I recently put a new LED bucket on my wife’s triumph and it’s the most emasculating experience riding next to each other at night. Her light is unfathomably more abundant, and the pattern and throw seem wonderful as well.
When I do whatever I’m going to do with the headlight, I’ll probably go the route of relays so as to not run main power through the switchgear, which I’m sure is less than mint in its conductivity.
This the part? You might have some luck finding one on Ebay or Beemer bone yard since these bikes get stripped for cafe projects that usually just leave an unrideable hulk and a pile of parts. I bought the whole mess of parts from BBY cheap after hitting a deer, the rattle can paint was awful which is why I went with the cameo scheme.
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This part. It’s been held together with blue painter’s tape since I first touched the bike, as that’s what I had with me at the time. I really should look at realOEM to figure out what it’s called precisely.
Post by: Kt88 on December 29, 2023, 10:19:59 PM
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Post by: Chaos on December 29, 2023, 11:45:36 PM
Post by: Kt88 on January 02, 2024, 11:36:50 PM
As it is, I’ll try this little experiment for a few days and contrast. The look I was going for was more CBR400f, but I think I may have landed more in the TDM 850 category.
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Post by: frankenduck on January 03, 2024, 09:18:41 AM
Well, I got impulsive and decided to be non destructively experimental and try two 30W LED 3.5” lights. The result, while not yet aimed perfectly, is massively brighter than the vintage foggy H4. I have to think that fresh ample gauge wiring, relays to cut voltage drop, and a healthy and clear reflector and the H4 would never have been questioned.
As it is, I’ll try this little experiment for a few days and contrast. The look I was going for was more CBR400f, but I think I may have landed more in the TDM 850 category.C9A4E015-E56A-4888-AE78-06ADC3BB4C49.jpeg (38.33 kB . 432x576 - viewed 775 times)
LED headlights generally tend to be "binary" (for lack of a better term) and aren't impacted by voltage drop like filament bulbs are.
Post by: Laitch on January 03, 2024, 10:02:52 AM
Well, I got impulsive and decided to be non destructively experimental and try two 30W LED 3.5” lights. The result, while not yet aimed perfectly, is massively brighter than the vintage foggy H4.What is the model number of the led lighting and the name of its maker, Kt?
Post by: Kt88 on January 03, 2024, 01:59:17 PM
LED headlights generally tend to be "binary" (for lack of a better term) and aren't impacted by voltage drop like filament bulbs are.
Sure, what I meant to express was that if my H4 reflector and glass had been healthy I’d likely have simply changed the headlight wiring rather than switch to a new kind of system altogether. As it was, replacing those components also was looking awfully pricey.
What is the model number of the led lighting and the name of its maker, Kt?
https://dv8offroad.com/collections/led-lights/products/dv8-led-fog-lights
Though I didn’t buy from this vendor, these are the same lights and housings. I snipped the ears of the buckets they’re in to allow for their proximity to each other and then attached those buckets to the plastic rectangular headlight adjuster frame.
Post by: Laitch on January 03, 2024, 02:13:34 PM
https://dv8offroad.com/collections/led-lights/products/dv8-led-fog-lights (https://dv8offroad.com/collections/led-lights/products/dv8-led-fog-lights)The site is devoid of technical details. Do they have a high/low function? Being fog lights, if they are fog lights and not just Jeep ornaments, the beams would tend to be wider, used in a downward direction, and not designed for distance. Aiming away from oncoming drivers will be critical. Let us know how they work out for you.
Though I didn’t buy from this vendor, these are the same lights and housings. I snipped the ears of the buckets they’re in to allow for their proximity to each other and then attached those buckets to the plastic rectangular headlight adjuster frame.
Post by: The Mighty Gryphon on January 03, 2024, 03:20:42 PM
I have nearly 100k on my assorted bricks, with a fair amount of rural riding at night. I have found that using the Eastern Beaver relay harness for the headlight and adding a couple eBay LED driving lights gives me all the illumination I need to see critters planning ambushes in the dark.
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An added bonus is that the LED lights are visible for at least 2 miles in bright daylight, making them excellent for conspicuity. It is very hard to not see me coming, even out of the corner of your eye.
Post by: Kt88 on January 03, 2024, 10:27:39 PM
From my experience with fog lights I am going to guess that the original headlight was in really bad shape for you to see such a big improvement. The silver on the reflector is extremely soft and if a previous owner tried to "polish" it they probably scratched it enough to diffuse as much as half of the light that is supposed to go downrange.
I have nearly 100k on my assorted bricks, with a fair amount of rural riding at night. I have found that using the Eastern Beaver relay harness for the headlight and adding a couple eBay LED driving lights gives me all the illumination I need to see critters planning ambushes in the dark.
You’re exactly correct. The glass was no longer transparent, the silver ring was utterly nonreflective, and the adjustment mechanism was broken as well. All the little bits added up to make a very unsatisfactory light.
The site is devoid of technical details. Do they have a high/low function? Being fog lights, if they are fog lights and not just Jeep ornaments, the beams would tend to be wider, used in a downward direction, and not designed for distance. Aiming away from oncoming drivers will be critical. Let us know how they work out for you.
As of now I assume the worst. The lights were sitting around and available, so I wanted to try a low impact proof of concept. I’ve not done any highway riding since installation, so I can only speak to around town riding. Since I had to attach them, I aimed them where I wanted. If I stick with this kind of setup, I’ll make myself a more robust bracket with more thorough adjustments than simply up/down. As of now I hit shorter cars around their hood or headlights, but I can’t quantify the distance the light is thrown either. It may very well be that they do not throw far enough for reliable, practical use. And of course you’re right that they are currently low beam only- I’ve not yet found a sealed hi/low 3” or 3.5” led light. When I do, I’ll use a pair of those instead.
Everything is reversible still, so if I do stumble upon a sufficiently thrifty stock h4 unit that’s actually healthy in the inside, I wouldn’t feel terrible about swapping back to compare.
Post by: Kt88 on April 05, 2024, 08:05:07 PM
Long time, no post. I got a set of fairly intense contracts over the last few months and haven’t had much “me” time for improving the K- rather, it’s been pressed into commuter service, which (even in its very much imperfect state) it’s simply excelled at. Though my ever present wandering eye has spied a deeply underpriced 1150 GS nearby, I’ve decided I’m going to at the minimum finish the job I started and get this 75s back to fully factory functional state before I make any hasty decisions regarding it and my perpetuity.
At this time, and honestly to my chagrin, several demons remain that have been very present since my ownership commenced.
Most importantly: I must rebuild or replace the front forks. South Florida has not been kind to the chrome or the exposed dust seals, the fork seals themselves are blown, their oil volume probably almost nonexistent and the function more akin to a non dampened pogo stick than they left the factory.
I have come to the conclusion that they are most likely the Showas, with a build date of 04/92 and the non-bulbous dust seals showing. Do we as a board have a preferred vendor for seals and rebuild kits? As much as the rust on the tubes isn’t aesthetically pleasing, it’s hardly in the functional area of the forks- mostly between the triples and the lower clamps, less on the wiping areas- and I’m not so vain as to replace solely for that… yet. I do want to stick to stock, and I’ve not yet had an earth shattering experience swapping springs for progressive, but I am happy to measure for fatigue in the stockers. I have to imagine that simply having the correct displacement of oil and seal function will be the biggest night and day I could imagine.
Second, I bought a long-deduct Works rear shock to replace the frozen unit that came on the bike. It’s an improvement in that it articulates, but the dampening is also clearly shot, and it being rebuildable makes me inclined to seek that rather than a 600-800$ replacement strategy.
Lastly, and maybe with the most shame- I’ve not yet diagnosed the constant brake failure warning light or the constant coolant temp light. All the attached systems function as expected, coolant temp looking ok via laser thermometer and brake lights and ABS functioning well upon observation. The odometer and trip meter are DOA at this time, so I may have a chance to look at the contacts leading to the gauges, anyway.
Other than those things it’s all cosmetics- fairing support, gauge face plexi (or plastic, actually, I don’t know the composition), and perhaps eventually some retouching of the seat.
Bluntly? I’m still in love with it, and its reliability, and as long as I’m wearing a helmet and don’t hear the countershaft gear TOO loudly the bike is silent and wonderful. I don’t think I’ll swap it for another R bike in the foreseeable future.
Post by: The Mighty Gryphon on April 05, 2024, 08:42:48 PM
As far as the rust, Evapo-Rust is a very good rust remover. It's about 18 bucks a quart at Harbor Freight. It's good because you can put it back in the bottle and reuse it, it goes a long way. After you get the rust cleaned up, rub the bare metal down with aluminum foil and put a light coat of oil or wax on them to protect the bare metal.
I have rebuilt my Worx shocks. It's pretty straightforward/they are fairly simple devices if you take your time.. You will need a spring compressor and someone who can charge the reservoir with 250psi of nitrogen. As I recall, there is a shaft seal and cap o-ring you might need to replace. There is a bladder in the reservoir that I think you can still get if it is bad. I have the link for it somewhere. Again, I use ATF for shock fluid. I also have the rebuild instructions somewhere, too.
Post by: Kt88 on April 05, 2024, 08:49:16 PM
I found a worx rebuild link somewhere here on Motobrick, I think, and it did convince me of the mechanical feasibility. Working in a no-mechanical-project-allowed building dampens that somewhat- but I can always do most of it in my actual apartment and then just take it out to put it back on the bike.
Post by: Martin on April 05, 2024, 08:51:19 PM
Regards Martin.
Post by: The Mighty Gryphon on April 05, 2024, 09:04:44 PM
It might be worth spending a few bucks to take it to a shop that services off road bikes and four wheelers to have the pressure released and the spring removed. Then have them re-install the spring and charge the shock when you are done with the rebuild. I would guess the cost to do that work would be about what a set of spring compressors will cost you. I think I paid $20 to have mine charged. It's a 5 minute job.
The trickiest part of the rebuild is the valving. As I recall there is a bunch of flappers and spacers that need to be in a specific order. Just be careful to keep them organized as you take them apart and you'll be okay.
Post by: The Mighty Gryphon on April 05, 2024, 09:16:46 PM
http://evolutionsuspensionproducts.com/Works.html
Post by: stokester on April 06, 2024, 10:47:32 AM
It's good to see someone is at least selling parts for a rebuild and I may give it a try.
Post by: The Mighty Gryphon on April 06, 2024, 07:11:08 PM
Not to hijack this post but I had the Works shock with remote reservoir blow out this past year on my R100RT and replaced it with a YSS. My searches and conversation with Ted Porter let me to the YSS model which is what I have on both my K75s.
It's good to see someone is at least selling parts for a rebuild and I may give it a try.
I had the seal blow out on my Works shock as well. That is how I got the rebuild experience. I was told by the counterman at the seal place that I needed a high pressure seal like is used in hydraulic cylinders. Apparently the previous owner may not have known that. I just used the seal that came with the rebuild kit and it worked.
Post by: natalena on May 12, 2024, 10:37:37 PM
Post by: K1300S on May 23, 2024, 07:35:16 PM
https://www.motobrick.com/index.php?topic=7810.0
Riding in Miami...btdt. sort of year round. I would park it in July/August. Too f'ing hot and humid to ride.
Post by: PitchlerBrick on December 20, 2024, 12:31:43 AM
"One note, and maybe I’m preaching to the choir:
Coming from airheads (I’ve had about 35 or so), I’ve always been told a k75 is a great engined bike, but has no character. Riding back under very far from ideal circumstances last night, I didn’t feel that way at all. I would have screamed for joy for my R bikes to run as smoothly as this abandoned k75 did last night. I would have started threads on ADV detailing how I got there. I’d have written novels about the smooth tractability of the power. Do people just not like the K architecture as much? The frame felt great, and I had NO rear suspension. I can only imagine how much more I’ll love it with actual function. Is this me having rose colored glasses on because I moved from a bike built in 71 to one built in 91?"
Having owned a couple of R bikes and a K100-RS, I agree with your comments 100%. A K-75 is a joy to ride, you are spot on.