Many years ago (probably 2002-ish) I bought a cheap GX160 'clone' Medusa SIP2300 from the local Makro outlet. It had very little use as around then I also bought a diesel unit (Petter AB1) which ran cheaply on central heating oil/red diesel.
With fuel prices going ever upwards I did consider converting it to gas (LPG) but all the kits were around the £125-150 mark, plus an expensive Garretson demand valve (although I have one of those from a different project) more than I paid for the generator. Anyway, with hints of power cuts this winter I had a quick look on eBay recently for 'generator gas conversion kits' and was pleased to see a complete carb and demand valve setup for 'GX160' type engines for £26.99 delivered. UK stock too and it arrived well packed and quickly.
A 15 minute job to take off the old petrol-only carb and swap this unit on in its place. It is still capable of running on petrol and there is even a drain tap on the float bowl to make change-over simple. I already had a length of Propane hose and a Calor regulator.
The demand valve assembly has a priming button (it just flows gas when pressed) and a crude 'mixture control' screw that simply limits the flow of gas out of the demand valve. Having used these things before, I did not bother starting with petrol and went straight onto gas. It fired first pull and with a few extra bursts from the demand valve soon settled down to normal running. I investigated warm and cold starts, if you know your engine behaviour on-choke (remember those??) or too lean its easy to manage. For a load I used a 1600watt paint stripping gun, very easy to switch on/off and a significant load does what you expect, the revs drop for a second or so before the governor responds and restores normality. AT this point I will link to a couple of documents written by John G8MNY as they describe a 'look forward' performance enhancer for this same generator. I have acquired suitable solenoids to rewind and will attempt to replicate his results. Well worth a read.
https://www.theskywaves.net/technical/P ... _Iinfo.pdf
https://www.theskywaves.net/technical/P ... epairs.pdf
https://www.theskywaves.net/technical/P ... 1_of_2.pdf
https://www.theskywaves.net/technical/P ... 2_of_2.pdf
And a whole host of other interesting and useful articles, many from the past issues of CQ-TV.
As to running costs and economy, LPG in a car gives about 5% less mpg than petrol, but is considerably cheaper per litre than petrol. Until a couple of years ago my car was running on gas for 9 years, the same kit was transferred from its predecessor where it worked for 5 years. Benefits were reduced oil fouling and 1/2 the CO2 emissions of petrol. On the motorway, my trusty old Ford Scorpios cost me about 10p a mile. For portable use, my radio club used to run their petrol generators off 19kg bottles, that's approximately 38 litres. Such a bottle costs around £50 for the gas at the moment but it tends to follow petrol costs. I have no idea (at this point) how much gas my generator uses.
Here is the one I bought. https://www.ebay.co.uk/itm/394125835627 which includes several pictures. The seller took an offer of £1 less
I know 'Inverter generators' are more popular these days (and 10 times (if its a Honda) what I paid for this one. Gas conversions are available for them too and if you already have gas on board (e.g. motorhome or caravan) and run a lot of generator, it might be worth considering.
Gareth