Despite trying hotter spark plug, up to 6 from 8, Siegfried disappointingly ran rich and out of uphill puff last time out. I consulted at length with Zweiradhaus Suhl who told me that the original BVF carb was never much good in the first place and that fitting their Mikuni carb conversion would cure any problems in the carb dept. As the £ is currently so strong against the Euro I decided their would never be a better time to get one so ordered everything necessary to do the job in one hit. It came with a new extra long throttle cable. Fitting this revealed a brilliant piece of clever engineering that I have not seen before. The throttle cable emerges from the twistgrip through a hole in the bars. I just thought that this was just German obsession with tidiness. The reality is that the Simson engineers realised that throttle cables snap due to metal fatigue about 1 cm away from the nipple as the central cable is coiled and unwound over and over as on a conventional twistgrip. Much better to have a straight line pull with no coiling. Thus the inside of the twistgrip tube has a raised worm drive. This mates to the slider which holds the cable nipple and which slider has a diagonal groove to accept the worm drive. The slider sits in a channel. As the twistgrip is turned so the worm drive causes the slider to move outwards thus pulling the cable. The cable exits through the bars because it has to. What a great little piece of engineering.
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