I have a 1125 on an st15 genhead (28 HP) It shipped with an attached fan cooled radiator, and 3 gallon fuel tank.. Louder than your Mother -in -Law , when you tell her she cant come along, but starts every time.
The first fault was the starter, a small high torque GM clone, had to have it rewound locally so it would hold together, ( the dealer was kind enough to cnnibalize another one in his inventory for a replacement, but it failed in short order also.) The next failure was in the cooling system, the radiator literrally shook itself apart piece at a time, I installed stiffeners, brazed the failed connections, but it finally was a total loss. I stripped the radiator from the set, and built a top motor plate with a couple of 1" pipe flanges one with a dip tube attached s to allow it to hopefully siphon cool through a automotive type radiator. It works GREA. By Scrapping the radiator, I lost the built-in charging system, so put in a stock 15 amp 110v automotive type charger to keep the battery in top form and supply the power for the radiator fan.
The next to die was the built in fuel tank, again it shook apart at the seams, drenching the monster in #2.
Once replaced with a seperate mounted gravity fed system, all has been well now for 50 + hours running time. I still have to find a way to quiten it down, both the exhaust and intake could both use some major engineering from an ccoustic standpoint.
Performance wise it is delivering well above expectations, it starts a 5 ton airconditioner and once running will start a 3 ton system, but not in reverse order.
Max starting load while starting our 5 ton airconditioner is 92 amps, It does a remarkable job delivering a consistant 65 amps while blowing some grey smoke using straight diesel.. fuel consumtion at that rate is 1.12 GPH. At 52 amps the fuel consumtion was exactly the same with the same grey smoke, at 19 amps consumption was .68 gph, Running no load at 2200 RPM it consumed .41gph.
Overall I am happy with Big BERTHA, Feeding it with Woodgas is no problem, but I have yet to find a realistic measurement of savings , though in a one hour test I have seen diesel consumption with a 52 amp load as low as .36 GPH. for a total savings of .66 gph over using diesel alone. Not yet where I want to be, but enough of a savings to make me want to continue to work with the woodgas project..
Best regards
Steve