Since we purchased Dusk and the the previous owners have had start problems with the genset .
They even had parrelled a smaller battery next to the genset which helped but in hindsight was not a good idea as the batteries were not the same.rating and the smaller battery was being overcharged so i was determined to try and resolve the problem.
I had the genset serviced and had the fuel.pump negative solenoid terminal block all replaced which seemed.to.fix the problem however within 24hrs i was back to square one.
The owner of the company who serviced the genset was extremely embarrassed and personally came out to try and find the problem. 2hrs later the problem seems.to be solved and bolied down to a faulty k3 relay for.the pre heat plugs as we are in the meditterean he said it was not neccassary to pre heat the plugs with he present weather conditions so he removed it and suggested i buy a new one when i got the chance he suggested to try and get a 70amp one as opposed to the present 30amp one
For 3.months we have not had a problem starting the genset with the realy removed whilst this may not be your problem it may be worthwhile removing the relay and trying it out.