Re: Are most/all 4 cycle motors regulated?
I don't think it has anything to do with cycles. I think it has to do with the size of the alternator/generator and the battery. On small engines usually there are small charging circuits (usually if electric start, sometimes if manual) which do not supply a large recharging current (like a Mariner 2 cycle 4 hp has an optional 4 amp, non-regulated alternator). With a small current, potential battery damage is minimal and no need to regulate it.
Hard to tell without actually seeing a regulator if regulated. Regulated power (when applied to the battery) would be much more stable than unregulated, which would vary wildly and directly with engine rpm's, but due to the batteries loading effect, with light current chargers it would take time for the battery to respond and the battery would load the charger and mask immediate reactions (charge voltage vs engine rpm's).
Like in one Mariner sales brochure I have, you have to get to 16 amps (specifies 85 watts) in a 40 hp engine before they regulate it.
If you are talking about outboard 4 cycle engines they probably follow the same senario. If inboard or I/O's the engines are usually large, the alternators are large and regulation is a must.
My 2c,
Mark
