Friday, January 18, 2013

Second Csepel Danuvia Ride of 2013

On my first ride of the year, one little problem I had that I wanted to resolve before I rode the bike again was the gas cap was leaking. As you can see in this photo the inside lip is mangled and the top edge of the opening is uneven, creating a situation where the gas cap will not get a good seal. I wanted to try to straighten  the inside lip so that the cap would fit tighter, but I didn't have any kind of plier that could get in there and do it. I tried adding another rubber gasket, but I still couldn't get the cap to cinch down tight enough to get a good seal. A thicker soft gasket tape might work, but I don't know how long it would last in an application like this.

I came up with another solution. I turned a little cup out of a plastic called Delrin on the lathe. It fits through the larger opening but has a lip with a rubber seal that prevents it from dropping through the smaller inner opening. It also has a few vent/drain holes drilled in it.

Here you can see it dropped into the opening. It had to be a cup shape to accommodate the way the underside of the gas cap protrudes into the opening.

The last little addition is a spring that holds the Delrin cup tight in the opening when the gas cap is put on. This seems to have worked pretty good. On my second ride I filled the tank up pretty full and I didn't have any leakage whatsoever.

Another beautiful January day can only mean it's time for another ride, and this ride was much better than my last because I didn't have gas leaking out of the cap every time I hit a bump!  I've been wanting to get some photos of the bike outdoors, so I rode it over to KC's Kauffman Performing Arts Center which is just a few blocks from me for an outdoor photo op.


  1. Nice bike! I got me an Csepel 125 too, mine is from 1949. I'm stille searching parts, but I'm almost at the point to get it together again.
    Are you Dutch?
    Best regards Eric Heijdens the Netherlands

  2. I've had good luck with a guy in Austria that goes by OK Team Classics or a guy in Hungary that goes by Eastern Two Stroke. Between the two, they've found anything I needed, most of the time NOS.

  3. Am I Dutch? No, as much as I'd like to live in the Netherlands, I'm located in the midwest part of the US