Hello expert moppetschrauber, we want to drive an “open” 50s because of the existing 4s-FS. Of course it would be easiest to buy a 4s. Unfortunately, these have become outrageously expensive. There our consideration is to rebuild an 80s (or even 125s) to a 50s which come then reasonably out of the hooves. Above all also because there is still a manageable offer here. We have not become so clever which models offer themselves, and gera For this reason, we are value-free in terms of manufacturer and type. As an alternative, maybe a 50’s mokick would be to “open”, but the parts are now also expensive, or those of which there was an open one, there are apparently few models suitable for it. At our TÜV I was, but they are stubborn in their statements and above all they want to know clearly a model. Do you have advice (e.g. which models are suitable for this and what to do there)- besides to make the A-FS? n Thanks to wool