Boxerworks.com

Working on the left cylinder of my 1981 R100RS (Nikasil).
No lip at all in top of cylinder, just a little bit of carbon.
Can still see the hone marks on the bore.
Piston (full dome 9.5 to 1 ?) stamped 93.97. Read all I can find
on Snowbum, this site and adv rider. Original top ring gap in
cylinder 0.58mm at upper edge of wear limit. New rings (Motobins)
top compression ring gap 0.45mm good.
Oil ring single rail will internal coil spring end gap 0.45mm .
Clymers states (P198 - all other models) 0.25 - 0.40 mm.
Also Snowbum states that iron bores and Nikasil bores do not
use the same material in the rings.
My new rings state R100/7 T, R100 T/C . Are these the correct rings
or have I got the wrong parts . Bins was given 5/81 R100RS and VIN 6077429.
Got to track down some Threebond for the cylinder sealant as yet.
Have read all about how to do it. I am presuming that the sealant has to be applied
to the cylinder base as well as to the crankcase. This is not mentioned anywhere
that I have able to find. Most sealants require both surfaces to be coated.
Advice, experiences , how you did it ???
been able

Don't know about the ring gaps Kutter, but with the three bond, I apply to the engine casing only.
Not much at all, but a consistent amount all around. Any excess eventually will be found in your oil filter.

Cylinder base to crankcase sealant: Where and how much.
http://www.gunsmoke.com/motorcycling/r1 ... index.html

The ideal ring gap is about .003" for each inch of piston diameter. Your gaps are a bit much, but I have found that they generally seal at those gaps. I have a few time put together an engine out of old parts and used rings that were far worse and they sealed up OK.

Too small is quite dangerous, as they will break and score the cylinder.

Hello !
Check that the rings have not too much play in their grooves.
This is THE limit; If too much play, the rings will rattle and break ruining the cylinders...
Also, clean as much as you can of carbon deposit into the grooves of piston. This carbon build up prevent the rings to rotate properly and cause rapid wear....

Yes, I have cleaned the carbon from the ring grooves
and the side clearances are at minimum specs.
Tracked down some Three Bond 1104 as used to seal crankcases
by the local Yamaha dealer.
Thanx for all of your input.!

Remember there is no clearance between the cyl and case. If you think you don't have enough sealer on it you probably have too much