I always wanted to do a restoration but have never found a bike for such a project, all that changed when I came across an old K100 looking very unloved indeed. I was immediately intruiged by its power train layout and after getting it home I started researching about these K bikes, and couldn't find a bad word about them. Went to the llocal BMW shop and was quickly brought up to speed on the issues I would face so I started researching. It was then I then found Berts restoration link on the web and started pulling her down to look at all the potential problem parts. It was then that I found this forum and was pretty much blown away by the depth of knowledge and support. My mission is to try to restore this bike both mechanically and cosmectically back to its former glory. So with all the usual parts ordered (oil pump shafts, seals all rubber parts etc) from Motobins and no doubt a bag full more required I am at the start of my journey to rebuild this fine old lady.

The old girl when I got her home









The stripdown











Hmmm output shaft seal or oring issue for sure the clutch showed signs of slipping as well


Next to check the engine insides to see if the rivits on the output shaft are loose as known an issue with the 84 and 85 models due to only six rivets later models had 12


Lucky for me they are ok

Now for the oil pump and known the original oil /water pump was cast iron and one cannot get the original seal kits anymore the bleeder hole had oil around it (buttom of the sump ) so one could assume that the seal had perished after all these years I was hoping that someone had done the pump update already though.





Unfortunetly for me it was the original pump inners seen by the cast impeller and the nut on the shaft not a bolt in the shaft. Had to order the shaft pressed impeller and the new ceramic seal kit from Motobins very reasonable pricing from them the prices locally were criminal.

Now the healing begins because most of the bits are very weather beaten I set myself up with the following



Each part requires restoration I want to leave all parts original looking so I practiced with the sand blaster and good old elbow grease (Brass wire brush and mild detergent.

Shown here is the alternator

Before







After









Result looks ok however I have ordered a ultrasonic cleaner like OG and I will see what that does for me OG has had some spectucalur results.

I will try VHT clear enamel on all parts at some stage in the near future has anyone had success with it on aluminuim parts?

Also pulled apart the starter motor and regreased the bearing and cleaned up



The sandblaster can be as bad as it is good no one want abrasives in the machinical parts I have been experimenting with mould release first then silicon below is a injector before and after

Go on - and don´t quail when times come harder

1st: RtfM for download here

Good work and great photos Halo.

No doubt there will be a few on the forum following this closely.

+1 blakey



great work halo ...sniffle reminds me of bringing home a corossion encrusted piece of aluminium crap as well...but with lots of potential ...

good onya mate! cant wait for more

Good stuff Halo,
They sometimes look pretty rough on the outside, but usually under the gunge they are remarkably sound.
I can see another concours job coming here.
Cheers,
Paul.

Looking good mate. Wish I had the patience but I just want to ride!!!!!

Wow! Impressive Halo. Slowly, Slowly catchy monkey! Great detail in the pics for those of us less gifted. She'll be super when all brought up to that standard.

88KE

Hey halo...seen this?

http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/

Blakey thanks for the link looks really interesting shall give it a good read tomorrow And comment

Be careful with that stuff...apparently it goes e v e r y w h e r e!

But, it's biodegradable, so if you do it outside, the next shower will wash it away.

Outstanding pics mate! Keep after it and I'm looking forward to this one. I've used the VHT before on calipers and what not and its decent stuff at a good price. Oh, and can I put in a request for documenting that oil/water pump rebuild as it was one that bit me in the a**!

Thanks,
OG

Thanks OG the work done up to now was before I started this post / forum so posts so far are more of just show and tell thing from now on I will try to document the main subsections. OG I really appreciate your comments as your resto just blows me away and is something I will try to aspire too.

top job halo
i thought about doing something similar when i got my bike but as soon as it started plans changed register now ride it do up later
blakey
like the soda blasting machine will have to give that one a try

blakey wrote:Be careful with that stuff...apparently it goes e v e r y w h e r e!

But, it's biodegradable, so if you do it outside, the next shower will wash it away.

Blakey is very right!!! for those who know of my backyard..It was all white!! And wear a respirator!! like breathing lemonade!!

Excellent work there halo.

Doesn't look abrasive enough for the engine (shes really weathered) I have machined up PVC plugs for the appropriate holes so the abrasive al oxide doesn't get in. I brought a gravity feed gun and will make a booth up to recollect the media I want to use it for the wheels and frame as well.

Blakey & Alby thinking of taking out the aluminium oxide in the sandblaster cabinet and trying the soda on the throttle bodies inside and out your thoughs guys

halo.. I found after I tried it, two things. 1. I needed to get the proper soda medium. 2. Needed at least 5 hp compressor. I ended up using the brass wire wheels.

Alby's right, you do need a bit of force behind it.

Lucky for me a good friend of mine has lent me his large air compressor for awhile mine is just a toy so that part is covered. I have tried the brass wire brush wheel and found it abit to harsh and doesn't give me that wow factor, what is the correct medium Alby and where can I get my hands on some.
Thanks
Halo

Can start to get cracking now the first shipment of parts has come in

ahh...nice ....i see the water pump kit and lots of goodies

halo, One of our local bike mechs uses a commercial soda medium. It is like a fine rock salt. It explodes on contact and the fine particles strip away the gunk. Just do a search for blasting supplies. there are many! I think hhis was in 20kg bag. i will ask him tomorrow morning if he is in town.

Thanks Alby it's my next thing to research and try

Albyalbatross1 wrote:halo.. I found after I tried it, two things. 1. I needed to get the proper soda medium. 2. Needed at least 5 hp compressor. I ended up using the brass wire wheels.

I was going to mention that the compressor needs some beef behind it. I saw that the compressor halo had looked borderline...might work, might not for soda blasting. I've a puny 5 gallon unit and it won't work at all.

Hi robmack got two compressors there in the picture the front one cheap the second one there (harder to see) is a $1000 jobby
Cheers Jason

Guys,

Went and got the following cheap parts today

Gloves $5 Tub $20 Soda $15 Gun $29 Vac $29 as I dont want to change the al oxide in the propper sandblaster cabinet. This one will be at an attempt to soda blast the throttle bodies.







Used the Old K100 air filter & will rig up the Vac tom & try the throttle bodies

Looks like you mean business Jason. One thing I found out a while ago is with those sand blaster guns if the tube that goes to the tub is a thin walled rubber get a plastic reinforced tube as the rubber one sometimes collapses wiyh the vacuum from the venturi and stops the flow of medium.

Thanks for the advice Kfreak yes I checked the tube looks pretty thick
Almost finished the Sodablaster it turned out fairly large I had some perspex laying around and used it for the top

The huge benefit of soda blasting is that one can wash the part in hot water and hey presto it is all gone whereas with sand or grit that will not dissolve and is there for ever. The trick is to get the amount of air delivery at pressure and the two compressors could probably be paralleled to give extra flow.
Regards,
K-BIKE

Had a chance to try the sodagun on the throttle bodies

Before





After







Really different finish to the sandblaster !!!!! will put it through 1 more time.

THANKS FOR YOUR INPUT BLAKEY & ALBY & K FREAK for this sodablaster I wasn't going to try one but now I have another great tool at my disposal for my resto.

I have been researching Ultrasonic cleaners and I will buy a ultrasonic transducer and design my own frequency and drive circuit. They say one centered on 40khz that sweeps 12khz each side is better. Then I can use a lager container, I have all the parts here but the transducer that is about $70 at Jaycar.

yes you have to find the resonant frequency of the transducer for maximum effect and efficency ...of corse as the transducer comes into contact with things ...(ie mounting with epoxy ) this will change quite a lot, so yes i would agree make it adjustable for the centre frequency

good job on the tbs....yay

Thanks charlie do you think the USC will do a better finish?

I see the ultrasonic cleaner as being best benefit in small holes/ports/chambers where crud has built up and there is no way for the soda to get in there ...same for threaded sections into body of device etc ,

i would imagine the cleaning fluid used in the usc would be dependant on the job also ..

maybe concider them both as complementary to each other ...if that makes sence (eg the usc would clean out the air bypass ports quit well through the tbs but best left for last after all the big stuff has been blasted off)

Yes agreed thanks Charlie

have been researching Ultrasonic
cleaners and I will buy a ultrasonic transducer and design my own
frequency and drive circuit. They say one centered on 40khz that sweeps
12khz each side is better. Then I can use a lager container, I have all
the parts here but the transducer that is about $70 at Jaycar.
_________________

halo..Those kit units are often on backorder!!! They will not be powerfull enough. They are great for small jobs. The energy is dissapated in the cleaning solution.HERE is some info for you.

Yes!! great job!!

Great article Halo, I'm hooked! Look forward to reading more as things progress.
Best
Dave

Yer thats Dave much appreciated

Cheers Jason

Alby wow you certainly went the whole hog that's a huge powerful unit. Unfortunetly out of my price range at present since I do design engineering I have quite a few sweeping frequency generators and complementary h bridge MOSFET driver supplies capable of high output currents hanging around you are right through the 50watt transducer from jaycar is too small i will have a word to our
Asian suppliers to see if they have larger ones pretty much I will try to find the biggest trunsducer for my buck and design a circuit for it.

halo_player wrote:Alby wow went the whole hog thats great. Unfortunetly out of my price range at present since I do design engineering I have quite a few sweeping frequency generators and amplifier supplies capable of high output currents I will try to find the biggest trunsducer for my buck and design a circuit for it.

Seeing as I am the original skinflint I am watching closely.

i think the secret is not to buy the biggest but have a look at watts per dollar, amongst the lower power units i mean 5x 30 watt units a 20 each could be cheeper than 2 x 80 or 100 watt .....if you get my drift

Yes agreed like the soda blaster I think I can make a low cost USC that gives you bang for your buck but Albys unit is sure sweeeeet

You have acess to frequency generators??!!!!! I may have a small request at some stage in near future. ill be needing something to punch out 10 -25 khz @ 140 db. I will be looking foward to your designs. A throw in type perhaps???

140 db out of what alby.... thats a pretty big number ....maybe one or many of those motorola piezios ...they have been used for bat scarers and stuff for years ...you would have to find the 100 watt versions though as the domestic versions 50 watt tend to blow up at those output levels. pretty flat responce from about 7 k up to 50k from memory

"You have acess to frequency generators??!!!!! I may have a small request..."

Dangerous words coming from the mouth of Alby! Be afraid. Be very afraid!

blakey wrote:"You have acess to frequency generators??!!!!! I may have a small request..."

Dangerous words coming from the mouth of Alby! Be afraid. Be very afraid!

aye blakey !!!!

ifn we get involved ...im making him sign a waver till we hi-tail it back to brissy ...

You guys, the thing is I wanted to do this project as it was a break from my electronic designs in my day job but it's all good and I will help out where I can. If we can keep it to K100's it would be a bonus though.
I'm still buzzing over what a good job the soda blaster does the finish is good and I don't have to stress about the foreign matter doing damage think I will try it on the engine block as I have the parts now and need to start to put her back together do you think I need to take the head off to have a look it's got 101 thousand k's on her

halo_player wrote:You guys, the thing is I wanted to do this project as it was a break from my electronic designs in my day job but it's all good and I will help out where I can. If we can keep it to K100's it would be a bonus though.
I'm still buzzing over what a good job the soda blaster does the finish is good and I don't have to stress about the foreign matter doing damage think I will try it on the engine block as I have the parts now and need to start to put her back together do you think I need to take the head off to have a look it's got 101 thousand k's on her

I would leave well alone. There are many bricks around that have done 3 times that distance and never been touched. Maybe just retorque it when the engine is still warm but do one bolt at a time. Like back it off pull it out and apply some antisieze on the thread and under the bolt head and then pull it up again.

Thanks K freak, thats at least one job I don't have to do then.

Jason

Jason,

I think you and Oldgoat are trying to make these bikes better than they were new.
The result looks very impressive.

CF