I think the only reason chargers say up to a certain engine capacity and fuel type is generally because the bigger the engine the bigger the battery, and this means the charger has a higher output.

Nevertheless, a charger will still charge any capacity of the same type of battery, it's kind of flawed as well, as some models have the same battery across several if not all engine sizes, for example I know a Cosworth has the same type as a lesser model, yours is most likely the same as well.

Martin