So I had just bought a k100RT. It was advertised as a k100rs. But meh, I had bought the bike for $300. Wasn't running, all the wiring taken apart in the front, battery is missing, no air in front tire. Fuel cap won't come off either.

Here she is, Kelly.


So here is what I have done so far:
-checked the splines in the rear, they look like they still retain quite a bit of grease.
-spark plugs have spark and it seems like the coils are doing their job.
-havent checked compression because the spark plug threads are a different size.
-oil change. (this oil was BAD)

-Hooked up the battery wires to the car battery on my car and tried starting her up with fuel in the gas tank. No luck. So I sprayed a bit of starter fluid in the air box and she fired right up, but then died. So I know there is a fuel problem. but I am not sure what to check first guys!

So My questions are:
-What do I check first for my fuel issues
-What are these two tubes coming out of the gas tank?VVVV

Welcome, Perkins. Resurrect that ol girl. 

I believe there are 2 venting hoses and, of course, the hose heading for the fuel pressure regulator. Start poking around the postings on this august forum, as answers abound. 

f'rinstance: https://www.k100-forum.com/t5568-photos-from-inside-the-fuel-tank and https://www.k100-forum.com/t6037-hose-replacement
And...here's one courtesy of the infamous Duck, master of all things K: BMW K75 K100 Repair Manual

Don't run that sludge any further thru the system. Consider it poison. A disassembly and thorough cleaning/replacement of hoses is in order, which is not too difficult, as the hoses can be found at a local auto parts store typically. 

 
In any case, remain patient; someone will be along shortly to assist you.  

In any case, remain patient; someone in a white coat will be along shortly to assist you.

Welcome to the forum.

You made a good buy at $300 for sure.

If the bike has been sitting you should change the hoses between the gas tank and the engine. You should use BMW hose, this is pressurised while the engine is running. They perish in time and crack. If you put them on a little longer you can afterwards move the gas tank back to access the relay box and the coolant radiator cap without disconnecting the fuel lines.

If the tires are over 4 years change them, it will love you for that.

The fuel system is a common issue on a non running bike being brought back to life. There are 4 screws holding the gas tank cap assembly in place and you will need these out to access inside the tank. But first you need the gas cap open.....It seems you have working sparks but so far no fuel but this may be dirt/blocked filter/blocked pump/blocked injectors but don't run scared as it can also be an electrical issue

Are there any clocks fitted?

Can you also post up the VIN number or at least the last 7 digits. Some parts of your bike seem to be later replacements. Also does the electrical plug to the gas tank connect front left or rear right [as you sit on the bike]?

92KK K100LT 193214 wrote:In any case, remain patient; someone in a white coat will be along shortly to assist you.

Welcome to the forum.

You made a good buy at $300 for sure.

If the bike has been sitting you should change the hoses between the gas tank and the engine. You should use BMW hose, this is pressurised while the engine is running. They perish in time and crack. If you put them on a little longer you can afterwards move the gas tank back to access the relay box and the coolant radiator cap without disconnecting the fuel lines.

If the tires are over 4 years change them, it will love you for that.

The fuel system is a common issue on a non running bike being brought back to life. There are 4 screws holding the gas tank cap assembly in place and you will need these out to access inside the tank. But first you need the gas cap open.....It seems you have working sparks but so far no fuel but this may be dirt/blocked filter/blocked pump/blocked injectors but don't run scared as it can also be an electrical issue

Are there any clocks fitted?

Can you also post up the VIN number or at least the last 7 digits. Some parts of your bike seem to be later replacements. Also does the electrical plug to the gas tank connect front left or rear right [as you sit on the bike]?

What is this white coat person? Also I have no idea what a clock is. Like the Odometer and the temp gauge? If so then those are the only things hooked up.

Also yes the last 7 digits are 0053254. The plug is at the forward left.

Kyle10 wrote:Don't run that sludge any further thru the system. Consider it poison. A disassembly and thorough cleaning/replacement of hoses is in order, which is not too difficult, as the hoses can be found at a local auto parts store typically. 

So the sludge would be old fuel? And yes that would be a start. How should i go about draining the gas tank of gas. The gas cap was also stuck onto the gas tank and it was ripped off by my buddy.



This is basically my work situation and some photos of the bike for reference.

My "garage" (built the fence yesterday)



(kind of a close up to the side of the motor)


Whats left of the gas cap 



Where does this ECU mount??!?!


Also this is the ignition I received from the original owner
I am not sure how to connect them up.

Nice . . . Love those Handlebars . . . looks like you've got a little bit to do on this one. I will leave it to the xperts but . .  .best of luck and . . . . I hope the complete . . . and entire . . . and utter overhaul / rebuild from the ground up goes well. I did mine and have no regrets . .  mind you , . .  mine WAS a runner from the day I got it. You obviously have still to sort this fact out

(and  . . . what they said about the men in white coats . . .we are all nuts for falling madly for these 20 year old + machines . . I swear it I do . .  I swear it . . . .   )

Jeez Perkins,

A bit of work there.

That fence is a good idea. They like to sneak out at night and find a friend.

Next thing you know you wake up one morning and there are two of the buggers in the pen.

Maybe you won't notice straight away, but the missus sure will.

Old fuel? Take the tank off.
Search the forum. Plenty of info to be had.

rosskko

wow. good on ya mate! bit of work there for sure. But no reason you cant make something decent.

Be prepared to spend a few dollars though, as your going to be buying quite a few bits and pieces I would say.

A full service 'kit' (filters etc), oil changes all round, coolant change etc etc all that obvious shite.

And be prepared to replace EVERYTHING in the fuel/air system thats made from rubber. The rubbers between the throttle bodies/head/airbox in particular

By the looks of things you will need a fuel cap rebuild kit and maybe even a new fuel pump (but you MAY get lucky on that one)

THIS PAGE (Max BMW) will become your friend. Its got all the diagrams etc for your bike.

The ECU is held in place by a plastic box which is suspended in place by 4 rubber grommet things mounted to the frame. The box is also an underseat storage area. 

Remove the fuel cap (4 screws), remove the pump, the filter, the hoses. take the tank of and turn the sucker upside down and give it a good wash out. Thats what I did anyways. The sludge is likely to be broken down rubber (from ethanol in fuel) and fuel mixed up. 

Gain access to the downloads section and look through all the information there (I did not do enough of this in the beginning)

My advise would be to strip it down to the engine and rebuild it - but thats just me. If someone really knows K's im sure they could get somehting like this and have it in a reasonable state of tune etc fairly quickly. But those novices amoungst us seem to fix one prob only to reveal another. And if thats ok by you, sweet - I just like to go through and get rid of the gremlins all at once (more or less) rather than over a year or 2. 

enjoy!

The 4 screws on the part that's on the tank need to come out. Sods law is they will be stuck and you may have to drill them out. try some WD40 or whatever you guys use to loosen them. The whole assembly comes off then you can then get your hand inside the tank.
You will definitely need a filter but you will need to check the pump and also the part it sits into.
Your tank you said has the power plug front left which I think means its the earlier tank [later ones have it at the rear]. The rear of the earlier tank is bolted down as in your photo.

There is a plastic tray goes under the seat and this computer slips into a slot on the base. They tray has a lid and is a useful storage compartment. The plug in connector to this computer will need to be cleaned up but go gently. A dodgy connection here will frustrate you later......

Clocks we refer to them as over here. As in the instrument panel od/rev counter etc. Yours is present.

I wouldn't be spending time building a fence. That wont stop another K appearing alongside. It happens in time and you cant stop progress!! I got one....it got hit from behind....got a second one...rode it home.

Ok, I got an 84 K100RT last year also in Baja Red and immediately set about a lot of jobs. They come apart quite easily and its worth doing at this time. A few days with the bike apart on the patio achieved a lot. Cant say it made me the most popular but it makes one easier to live with! Ks do that. I got a lot of fiddly things done and replaced the white cable ties with black ones. Its not cool to have white cable ties.

As the guys have said, take a lot off at the airbox/intake etc as this is where the robber perishing happens. This takes a little time but it is not silly money. Fuel lines, hoses, breather pipes etc if they go wrong create problems and are cheap. Things like the cooling system pipe to the expansion bottle, the little sight tube on the side of the bottle. Get all these right at this time because getting at them later means taking a lot of stuff off and once sorted they will stay sorted. Longer fuel pipes mean you can pull the tank up at the rear to access relays and can also slide it back to access the radiator cap [clean the inside of the cap too].

My take on brakes is do the master cylinder repair kits front and rear. It may seem like an overkill as they will probably work fine but I always found a resurrected K will fail not too long after you get it going and cause frustration. Goo inside the brakes and perishing of the seals will have occurred. New fluid, new seal kits. Calipers may be ok and your rear disc [rotor] has already been changed. My front one went from perfect to a solid stream of a leak under the master cylinder in 10 miles.

The electrical connections will need to be cleaned up, do them one by one. I wouldn't go pulling the wiring off the frame, just go through each one methodically, one at a time.  There is another electronic unit up under the headstock with a multi pin connector. Two bolts loosened and it will slide back. Clean these connections too.

For what its worth it looks fairly decent to me for $300 and a little time sent painting he frame while you have the stuff off will make it look good.

The engines are generally very robust and the only thing I think you may find coming at you are seals and the water/oil pump. I had to do mine in April and its a little tricky to get right. You can either find coolant getting into the oil so when you have it up and running keep a good eye on the coolant AND oil levels. If you have the spark plugs off do not lose the little screw on bobbins on top of them. You need them as new plugs wont have them.

If you are going into the engine/gearbox connection after a few year sitting the engine output seal may not be the best.

If you are working on the K don't be tempted to try starting it if the battery is a bit low. You can weld the starter relay contacts and shag them up- new relay. While you are in there put in a headlight relay if there isn't one fitted by a previous owner. It will prolong the left side switchgear.

In over 4 years a K has never let me stranded. Yours will reward you as well.

92KK K100LT 193214 wrote:I wouldn't spending time building a fence.
wont stop another K appearing .
It happens
They come apart quite easily
replaced the white cable ties with black ones. Its not cool to have white cable ties.
This takes a little time but it is not silly money.
Fuel , hoses, breather etc
Get all these right at this time because getting at them later means taking a lot of stuff off
New fluid, new seal kits.
electrical connections cleaned up, .
wouldn't pulling the wiring off the frame,
just go through each one methodically,
Clean these connections too.
The engines are generally very robust
the engine output seal may not be the best.
If you are working on the K don't be tempted to try starting it if the battery is a bit low.
put in a headlight relay if there isn't one fitted by a previous owner.
In over 4 years a K has never let me stranded. Yours will reward you as well.

In a nutshell.
92 does go on a bit, but what he says is sound.

For Ros  sko....

I was trying to put up a beer one but someones robbed them all.....

To be clear, I had built the fence so my four year old brother wouldn't get into the area and hurt himself. haha

So today is the first day I'll be able to work on the bike and my list was:
Remove fuel tank
empty fuel tank
inspect/clean fuel tank
buy a battery
learn about the fuses within the K-bike and fix burnt ones if there happen to be any.

However, while sitting on it last night and thinking about riding it I had realized that the fuel tank is leaking out the side!!! I ended up getting my hand covered in gasoline :/. It isn't even that bad of a leak. It is on the bottom left edge under the knee pad area. It just kind of dribbles. However I still don't want to deal with it and I am thinking of buying a new or used gas tank. If anyone has a gas tank for sale I would love to buy one! (obviously a gas tank in decent condition)

Perkins wrote:  . . that the fuel tank is leaking out the side . . .

Normal ..  well known K trait. Yep. This is what they do.

Finding a fuel tank in good condition is difficult but not near as difficult as raising a mortgage to pay for it so try this it works very well and IS permanent http://www.permatex.com/products/product-categories/specialized-maintenance-repair/professional-repair-systems/permatex-fuel-tank-repair-kit-detail

As a bit of advise; don't be too hasty, take your time. These bikes are very easy to wrench on, but as above already stated all (!) electrical connections need to be clean(ed), the air system needs to be without leaks and the fuel system clean :-).

Spend some time reading through the site and the fault-finding info on the portal page and you'll get there. The engine is normally very solid, so its the bits around it that might make you think   

If you have questions, let us know, but please read-up? Not a lot of difficult technical stuff here, more loads of practical tips.

Make sure you put your bike description with year or your VIN number in your signature, that makes helping out a lot easier as there have been changes through the years.

Good luck with the project!

By the way, the fuel tank cap is fitted the wrong way round, the water drain from the tank recess is blocked off in that position.

Paul.