Portable Honda Petrol Generator Not Producing Enough Voltage

[Harry Palmer]

Hi,

Trying to get to bottom of my portable petrol generator voltage issues, engine is a Honda GX160 with a non-branded generator 240/110v outlet bolted on to it, recently started her up with a very weak current, multimeter showed only half the voltage being generated e.g 240v outlet, actual =120v and the 110 v outlet actual = 50v

I don't presume to know much about portable domestic/light commercial petrol generators hence my polite request for guidance/help. I have attached several pictures of both the actual Stator assembly and Rotor etc for illustration purposes only
hoping some kind knowledgeable soul will point me in the right direction. The Honda petrol engine works fine and when I plug a 240v drill in the outlet socket I can hear the engine rev up under load but the voltage is not enough to power the drill, also tried other 240v power tools and a hair dryer and same result, I am familiar working with a multimeter but I don't know how to test if the Rotor and or Stator assembly windings have had it, the generator is a brush-less type, I see no scorch marks on both windings and have replaced the 16uf capacitor for new with no difference, any help in diagnosing to determine the cause of the low voltage would be greatly appreciated Ps. placed to multimeter to test for current on the two black wires (just slightly out of shot) witch attach to the capacitor and I am getting 14v AC reading, if that is of ant help - Thanks in advance

 

[Rockingit]

If the engine is spinning at speed (1500rpm final spindle speed) then sorry to say more than likely you have a burnt out winding

 

[Harry Palmer]

If the engine is spinning at speed (1500rpm final spindle speed) then sorry to say more than likely you have a burnt out winding

How do I check the RPM please?

 

[UNG]

How do I check the RPM please?

Google hand held tachometer gauge

 

[Harry Palmer]

Google hand held tachometer gauge

Thanks, but what I would really like to know if possible is how I test the windings on both Rotor and Stator assembly for the correct resistance and what the readings should be on the two parts if good?

 

[Avo Mk8]

The T25-4 diodes seem to be forming a bridge rectifier arrangement connected to the rotor windings.

I'm not up on generators, but I gather there can be an issue when after a long period of no use, residual magnetism in the rotor that is needed to get generation going, drops to such a low level it doesn't start properly.
There's apparently a technique of "flashing" the armature with a car battery to give it magnetism. I know nothing about this other than if not careful you can kill the whole thing for good !

There must be some on here familiar with these things!

I can't answer your queries about winding resistances I'm afraid.

As a matter of interest, are there slip-rings or a commutator on the far end of the armature that's not in the photo's - or nothing? (Having done a little more research, I think it's probably 'nothing')

Finally - irrespective of the connectors on it, are you sure it's actually a 240V generator (I imagine it is), and not a 110V one? Does it have a rating plate with details?

Edit: with a bit of scrap magnetic material (but not itself a magnet!) you could check to see if the rotor has reasonably strong residual magnetism, or none!?