20 Most Recent 1986 BMW K 75 S Questions & Answers

Check fuel, spark and compression. Spray starting fluid or carburetor cleaner in the carb, and try cranking over. If that does not work, check the spark plugs and see if it arcs when you turn it over no arc means a bad wire or coil. If you replaced that and it still does not work, you know its getting fuel and spark, you may be running too rich and it would not be a bad idea to check the carb jets.

The starter relay has welded contacts and requires replacement. This is a fairly common problem with older K bikes.

there is an electrical box in the area under the seat... I can't remember exactly which relay it is, sorry.

look on e-bay for manuls or go to www,maxbmwmotorcycles,com
you can get all you need from this sight
mike,t

With everything undone use a rubber or plastic mallet to slide the forks out

The gear moves out to engage and back when it starts, SO the starter may be shot or the gear needs cleaned and lubed

... as in you turn the key on and the starter starts running? I would look in two areas..First, find and check the start solenoid. I think it may be stuck in the 'closed' position. This could be due to one of two reasons: 1 - it is physically stuck, closing the contacts in this electrically operated switch - 2 - there is a short in a wire that keeps the solenoid charged all the time. When you press the start button, the solenoid (an electric magnet switch) is charged, pulling a plunger into a position where the battery is connected to the starter. When you release the start button, the electric magnet is turned off and the plunger (with the help of a spring) is suppose to open the contact turning off the starter.The other reason is mechanical. The starter gear may not be releasing from flywheel for some reason, probably a lever or weak or broken spring. I am not a BMW expert, but those are the things I would be looking for in your case. Good luck with your project and thanks for your interest in FixYa.com

you could try not engaging full choke and letting it warm up for longer or look at carb ballanceing?

search salvage yards online or european bikes mags--------archway in st louis may have one-------aftermarkets mite not work rite---germans made ur scooter--also see if u can repair it-buy a haynes or clymer manual for the bike

I would recommend a leak down test to distinguish if the low compression was due to ring wear or an issue with the valves/seats...cylinders bores dont just wear out from sitting.
It's very possible that the valve seals were worn allowing crankcase oil to seep into the combustion chambers, thus causeing it to smoke. Being a 3 cylinder water cooled engine it should not have an overheating issue to cause the rings to stick...unless it was neglected, and not regularly serviced, debris in the oil filter, low oil pressure.. sludge from worn out oil. A good clean air cleaner is important...bad filtration will cause premature engine wear. Install a K & N high flow filter... and your good for the life of the bike.
Hope this answers your question...good luck with your bike.

try e-bay there are lots of manules on there for the k75 there all the same bike even the k75rt's will do you or if your good with computers go to www.maxbmwmotorcycles.com that should help as well,,,ps,,there should be no parts left over????

probly not gitten spark cause ign is worn--may not be gitten proper fuel intake also--bike is old so du a compression test

ok get some wd40 or switch cleaner and give the handel bar switches a good socking give the cut out switch a good going over this switch is most likle to be the one playing you up,,dont try to strip the switch down its full of tiny little bits that will go PING!!! and you will loos them then?

I am not a motorcycle expert, but I'm guessing your float needle is stuck, asuming you don't have fuel injection. Add a few ounces of Chevron Techron to your fuel tank. Then spray some starting fluid in the air intake, usually under the seat, and see if it starts then.

you will need to get the service manual for this. i need to give you illustrations that the manual has plus tune-up specs.

Haynes manual

http://www.carlsalter.com/download.asp?fileid=066077087095095107049048048032038032107055053032072097121110101115032077097110117097108046112100102

http://www.ascycles.com/detail.aspx?ID=1767

The battery hides just underneath the rear of the fuel tank. The video shows how to replace it by lifting the rear of the tank. This is the new battery specifications

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