1990 K75

[rwinn]

Hello, new to the forum, new to BMW's but new to riding. I currently own a 79 Kawasaki KZ650 that I took down to the frame and rebuilt in a Cafe Racer style. I belong to kz650.info forum where my build is documented. I'm ready for a new project and I'm considering a K model. From what I've read they are considered very reliable bikes. So here's what I've found. 1990 K75 with 58k miles for $2000. has a fairing but missing the windsheild. Titled, and inspected. 60k service was done @ 57k and rear drive bearing replaced, Speedometer not working and the owner claims it's sensor in the rear wheel. Starts and idles well but when I chopped the throttle it bogs a little but catches up. Slow twist is fine. Some seapage but no leaks found and the tires are new. Also maybe you can tell me about any performance up grades available for these bikes, exhaust alternatives (slip on's ). Is there a conversion for the single rear shock to be relocated inside the frame. I would want to go with a smaller speedo/tach unit so speedo is sensor what about tach? I have also noticed some bikes without the fairing but have a radiator cover. Is that part available out there? Anything I should know, consider, or watch out for would be appreciated. Thnx in advance.....Rod

[Major Softie]

There are multiple K75 models, so we need to know what one you are looking at. There are a couple different fairings, and I THINK the C model (tiny handlebar fairing) and the "regular" K both have the radiator cover you are talking about. S and RT models have frame fairings. There are also (at least) two different tanks - RT tank fits better with the RT fairing and has different sidecovers. The radiator cover is probably still available from the dealer, but no doubt cheaper on eBay or possibly IBMWR.org Marketplace.

I do no believe the shock conversion you speak of exists. You would probably have to fabricate that yourself.

I don't know if anyone still makes an exhaust, but they certainly show up on eBay occasionally. Staintune and/or Laser Duo-Tech's may still be manufactured.

Anything other than perfect running usually is a sensor issue with the K's. Temp sensors are known to fail eventually, so that's the first place I'd check, as that will throw your mix off.

There's nothing in a smaller speedo/tach made just for the K, so you'll be looking at the plethora of aftermarket universal units.

The FI sensors are the only thing I know of that fails occasionally on these bikes. Other than that, the powertrain lasts virtually forever. Coils are one danger spot - not because they often fail, but because, if they do, they are stupid expensive.

I see lots of stuff on eBay for the K's (more for the 100, but there are some parts that cross models).

[rwinn]

Thanks major. This would be the small handle bar variety. I plan on removing the fairing if I purchase it. There's also a K100 I found for $2350 that has a larger fairing or at it appears that way. I'm a Boxer newbie but love the lines of the older bikes even the R models. I'll start looking for Coils, heat sensor and such to get an idea of cost.

[rwinn]

Found coils as low as $25.00 for a set, lots of Mass Air Flow sensors, one Temp relay which I'll assume is for over heating. haven't been able to find FI sensors or a Temp sensor. Looks like there's lots of stuff on EBAY which is good. I did see a set of progressive shocks that said it was for a K75. Is it possible to have two on either side as opposed to one?

[Deleted User 287]

Is it possible to have two on either side as opposed to one?

Not unless the frame has been drastically customized.

[rwinn]

Thnx Rob

[Major Softie]

Found coils as low as $25.00 for a set, lots of Mass Air Flow sensors, one Temp relay which I'll assume is for over heating. haven't been able to find FI sensors or a Temp sensor. Looks like there's lots of stuff on EBAY which is good. I did see a set of progressive shocks that said it was for a K75. Is it possible to have two on either side as opposed to one?

Curious about what coils you found. The were really pricey last time I looked, but it's been a few years.

Sorry, but when I said "FI sensors" I was referring to the mass air sensor, the engine temperature sensor, crank sensor, Throttle position sensor, ambient air temperature sensor, and any other sensors the bike has. They all talk to the FI brain. I didn't mean to imply there were sensors called "FI sensors."

My guess is that the seller of the set of shocks for a K75 didn't know what he was talking about. Either it's not a pair, or they are for a different bike.

[rwinn]

I figured as much although I have seen models where it appears to have the shock on left side and most on the right. I wonder if there might be a place to switch sides but I Guess not. The coils were found on EBAY. There were several and of course used. The lowest $25 and they went up from there and several @ mid $30's range. Actually I found the prices fairly reasonable. I have to admit all the electronics make me a little nervous. My old Kaw is very simple, but heard these are very reliable. I'm going to look at R models as well. Thanks for the input!

[Rebel]

All in all, I think you will be pleased with your bike. I used to have an '87 K-75S, and put 80,000 miles on it before getting rid of it. I had a lot of quirks, especially with the early Motometer speedometers!! I used to pull the connector on the back of the pod and spray the pins and connector with WD-40. WD means "water dispursement", so that would help some, but not always. These bikes were smooth and had a lot of torque. From what I remember, there are no modifications for the shock as you are wanting. You can easily tell the model by the back wheel. The K-75S and I believe the RT also had a rear disc brake, and the other models had a rear drum brake. That should help you in the fairing search, if desired. As with other BMW's I would be concerned with clutch spline lubrication, but I cannot think of too many other issues to pass on. I would make sure the rubber plugs are still in place on the rear of the centerstand. I lost mine and my centerstand rusted and broke. The engine was trouble free and I never even needed to adjust the valves in 80,000 miles. About the only thing I was ever curious on was WHY did BMW make the bike with the rear wheel so easy to remove, and make a front wheel that has to have both brake calipers removed to remove the wheel?????