The Airheads Beemer Club is a non-profit club reclaiming the 'Legendary Motorcycles of Germany'

Topic-icon Introduction / New Member

3 months 3 weeks ago - 3 months 3 weeks ago #4729 by 1559
Replied by 1559 on topic Introduction / New Member
welcome to your new family.
I 'll suggest that you find 1 or 2 local tech sessions to attend in your lo-cal and discover the in's n out's of airhead wisdom. lot's of folks to help you along this sickened path.

many have said what can be done. the rebuilt M/C should have been re-sleeved as won said the old was probably pitted badly. i did mine because I wanted to stay w/ the type pushing juice to 2 4pot brembos. there is a trick to installing the seal kit hopefully the PO did this correctly. best to ask him . also the 2 0-rings are an issue to find and they MUST BE ..... EPDM type 0-ring material. they can NOT be regular store bought viton, buna etc....... only EPDM will hold up to brake fluid !

I used some fine Crocus Cloth, wrapped around a dowel and carefully worked it with some light solvent. It took a while but the bore ended up clean, pit-less and shiny


a better idea imho, is to find a 1/4" steel rod, use a hacksaw to cut down the end a slit so i 1" piece of cloth backed sand paper/ crocus/ cloth sanding media could slip down the slit, use a drill and not a dowel.

you might try this, mine was too pitted and I wanted to do this process ONLY ONCE. hence the SS re-sleeve.
contact Mark
Re-sleeves BMW motorcycle master cylinders:

Machine shop still in business,
Still sleeves in stainless only
Phone number did change to:
800 528 5235

Address is still the same though
Mark Frappier
82 Mountainview Street
Agawam, MA 01001

Another often over-looked renewal point is the plug wires and plug caps. The wire MUST be non-suppression metal core plug wire, which can be hard to find. Caps are typically replaced with 5K Ohm NGK plug caps

I beg ... not really .... to differ. the solid 'wire core' is a stock item @ any flaps.
flaps = Friendly Local Auto Parts Store
same with the ends. be sure that you solder the ends to the coils side by pushing the wires thru the triangle hole, splaying them, solder and trim by sanding the barbs smooth. see pics.
there are a host of online shops that sell the 5KΩ caps besides Cr'amazon' !

those ends screw into the plug wires so that is a solid contact. measured w/ a VOM you'll get 5KΩ resistance. between the 2 wires end to end w/ a VOM & coil should be something like ....

9. TESTING coils & ignition caps:

a. The QUICKIE test is to remove the spark plug cap from both the left and the right cylinder
 spark plugs, and then insert a long ohmmeter test lead into one cap, and the other, at the
 same time. You are then measuring the total resistance of the spark plug caps and the coil (s). The reading MUST NOT be infinite or in the hundreds of thousands or higher....that
 signifies an open coil, open cap, bad wiring, or some-such thing.
The reading SHOULD be

13K to 18K ohms on the POINTS bikes;

and up to 30K on the bikes with the original molded
 non-separable spark plug cap cables.

. Harry

Last edit: 3 months 3 weeks ago by 1559.

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