Reviving a 86 K100RT from a long sleep

[rvleugel]

Hi guys, brand new to this forum and brand new to K bikes! I own a few BMW bikes (r100GSPD, r75/7, r100RT) and have just purchased a 1986 K100RT, sight unseen for a few hundred dollars.

The bike was bought by its previous owner as a lot with some other bikes. It doesn’t have a key, no history whatsoever other than it hasn’t been run in quite a while. Everything looks to be there (but I am new to the model!)

I’m after some guidance on where to start to safely (as I’m not harm the bike) start in getting this thing running again, for the first time in many years.

Any advice appreciated!

Thanks,
Rhys

[frankenduck]

I don't know if it really makes a difference or not but I figure it can't hurt. What I do when bringing a K back from the dead is pull the spark plugs and spray some fogging oil in each cylinder before trying to turn the engine over so that the cylinders aren't initially dry of lubrication.  (If you've never heard of fogging oil it's aerosol oil that should be sprayed into cylinders before vehicles go into storage in order to keep them lubed.)

[rbm]

Ted Verill wrote an article many years ago for new K-bike owners.  It's here.  Read it through as it has very good advice.  Also following Bert's troubleshooting guide here will help when it comes time to fire up the beast.  Finally, Duck has a website here that has tons of information about K-bikes.

[rvleugel]

Thanks for the info guys, some great resources there!

Specifically though, is there any things I should really do before turning the key (when I get one!) for the first time?

Cheers,
Rhys

[jad01]

In addition to what's already been offered here, I'd suggest you be sure the battery is in good shape (new) and fully charged, and that the ground connections are all clean and making good contact. Low battery charge or poor capacity (old battery) can cause the starter relay to stick and the starter to stay engaged.

[frankenduck]

There's a 99.997% chance that you will need to replace the crankcase breather hose. Part 11151460480

It's an oddly shaped hose that goes from the top back of the motor to the rear of the air plenum above the throttle bodies.

Link:
https://www.realoem.com/bmw/enUS/showparts?id=0504-EUR-10_1983_K589_BMW_K_100_RT_84_0504,0505,0514_&diagId=11_4676#11151460480

You'll probably want to get a new fuel filter. BMW ones are stupid high priced so an aftermarket is preferred. Don't know what's available in OZ but in the US a NAPA 3032 is what I use.

Oil filter: Bosch 72161

The three little black rubber caps on the throttle bodies should probably be replaced too as those dry out and crack with age. The BMW part is 13547694924 but any cap that size will work.



You should also inspect the fuel lines inside and outside of the gas tank.

When you first start it it may put out TONS of smoke.  This is a non-issue. When K bikes are left on the side stand the oil behind the pistons seeps past the rings into the combustion chamber.  This is especially true on 88 and earlier bikes before the piston rings were upgraded in 89. If you just let it run for a few minutes then that oil will burn off and the smoke will go away.

If you know that the fuel pump is working but it doesn't start then pull the spark plugs. If they are dry then the fuel injectors may need to be serviced as those can get clogged if a K has sat for many years.

You might find these links useful:
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/genmaint/K_Bike_General_Maintenance_V1.4.pdf
http://www.kbikeparts.com/classickbikes.com/ckb.tech/ridermanuals/K100.Rider.Manual.1988.US.pdf
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/optips/Operating_Tips_For_A_K75_or_2V_K100.pdf
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/shopmanuals/BMW_K75_K100_Repair_Manual.pdf

More links:
http://bit.ly/new2kbikes
http://bit.ly/kbikemandm