Terry,
Check out this article - with a picture from the factory showing where it goes.
The 25530-37 is a little disk which fits inside the hollow 25111-53 bolt. It's about 1/8" thick. If I remember correctly, it's rubber-like with a metal disk encased in it. There should be a copper/brass washer that goes with it. It's a one-way valve which uses engine vacuum to suck excess oil out of the chain case and back into the crankcase. One side has a small hole and the other side has a large hole, but I can't remember which is which. You're going to have to suck it to find out which way it goes.
The 52-53 Ks had all kinds of chain case breathing and filling up with oil problems. Sometime during 1953 the factory came up with the syphon tube idea. The first mention of it is in the 1954 Spare Parts Catalog, and it shows the -53A tube. There probably was a very short-lived -53 part, but I don't think anyone knows the difference.
- 1954 Spare Parts Catalog
- syphon.jpg (32.88 KiB) Viewed 10480 times
At 55 KH 1300, the factory drilled a hole near the bottom of the chain case and into the crankcase. They used a different one-way valve, the 25075-55, and abandoned the syphon tube. The 1956 Spare Parts Catalog shows both.
- 1956 Spare Parts Catalog
- syphon2.jpg (37.6 KiB) Viewed 10480 times