My house has a properly wired (I assume) NEMA 30 amp-120/240 Volt generator inlet receptacle (l14-30) which was designed to handle say a 4000 Watt generator.

However I only own a 2000 Watt-120 Volt generator that has two NEMA 20 amp/120 Volt outlets (5-20).

Can I safely make a conversion cord to hook one of these outlets to the inlet receptacle and power both electrical bus bars at the main ciruit breaker panel?

I know that only 120 Volts are available so I will just have to keep all of the 240 Volt circuits switched off.

I also know that I have 16.7 amps max and will have to carefully manage which 120 Volt circuits I switch on.

The main circuit breaker panel has the necessary interlock switch (this is why I assume that the whole generator inlet circuit has been properly wired).

I'd rather not buy a bigger generator until I see if I can live with the smaller one.

I'd rather not rewire the existing generator circuit.