Fuel tank approx. 35 ccm, shaped for the Weatherman Speed model
Adjustable uniflow by means of a common brass tube Ø3. Contact me for explanation.
A plug is available for the Ø19 hole in the front end.
Look for "Plug for fuel tanks" at this site.
Seal off the plug with an O-ring Ø15 x 2. Silicon for glow and nitrile for diesel.
Secure with a few drops of thick cyano on the outside for easy removal.