Diagnosing champion generator.

[38racing]

Hmmm. Without the actual model number it is hard to look up any info on this generator.

Being a gasoline powered it will be most likely a two pole alternator that must run at 3600 rpm (60 hz, USA)under load and run at 3750 off load; unless, it has an idle down feature. They simply not normally designed to idle. Even if it has an idle down feature 1500 seem too slow. Now if this unit is being on a 50 hz electrical then it must operated under load at 3000 rpm.

Besides the operating frequency is very important for most electric motors and critical for some electronics.

The only generators the operate under load at 1500-1800 rpm are diesel power unit with 4 pole alternators.

Model was posted above. Champion c46535 with 196 honda clone. It's a garden variety that should run at 3600.

[Arkie]

I've seen electronic ignition issues act like carb issues.
Timing advance built into the electronic magneto causing issues with advance.
Magnetos for a 6.5 clone can be found for $10 or so.
I would take a closer look at the valve timing vs the piston TDC. I've heard rumors of some of the similar engines where the plastic cam gear or similar displaced somewhat on the camshaft to where the valve timing no longer matched the piston timing. (think this was more common on some vertical shaft engines, not sure about the 6.5 though)
You have kinda a weird one if the valves, carb, intake manifold, compression, and new spark plug of correct type seems ok.

How does it act if you operate the carb throttle linkage manually from idle and gradually trying to increase the rpms?'
Does the engine start up easily?

[KE4AVB]

Hmmm. Without the actual model number it is hard to look up any info on this generator.

Being a gasoline powered it will be most likely a two pole alternator that must run at 3600 rpm (60 hz, USA)under load and run at 3750 off load; unless, it has an idle down feature. They simply not normally designed to idle. Even if it has an idle down feature 1500 seem too slow. Now if this unit is being on a 50 hz electrical then it must operated under load at 3000 rpm.

Besides the operating frequency is very important for most electric motors and critical for some electronics.

The only generators the operate under load at 1500-1800 rpm are diesel power unit with 4 pole alternators.

Model was posted above. Champion c46535 with 196 honda clone. It's a garden variety that should run at 3600.

Sorry I am guilty of not reading fully the whole thread.

With model I download the operator manual and there is no mention of an idle down feature. So this generator is not meant to run at 1500 rpms which is probably your problem of not getting it to idle smoothly.

[38racing]

I've seen electronic ignition issues act like carb issues.
Timing advance built into the electronic magneto causing issues with advance.
Magnetos for a 6.5 clone can be found for $10 or so.
I would take a closer look at the valve timing vs the piston TDC. I've heard rumors of some of the similar engines where the plastic cam gear or similar displaced somewhat on the camshaft to where the valve timing no longer matched the piston timing. (think this was more common on some vertical shaft engines, not sure about the 6.5 though)
You have kinda a weird one if the valves, carb, intake manifold, compression, and new spark plug of correct type seems ok.

How does it act if you operate the carb throttle linkage manually from idle and gradually trying to increase the rpms?'
Does the engine start up easily?

Hard to reach the linkage especially with the vibration. When off there is lots of spring tension when I pull governor lever towards low speed. I don't think its fuel as I checked flow to carb and fuel actually leaked from bowl until I realized the drain nut wasn't tight. On the air leak aspect I could pull the intake spacer and check for crack. I thought about valve timing. Maybe time to pull out the degree wheel. I did that sort of thing 23 years ago when I tried racing a go kart. The Hondas had the crank gear pressed on and practice was to remove it and turn slightly to alter valve timing to achieve 6000 rpm. Maybe the reverse happened here and gear shifted the other way. Also just remembered that I have another running clone that might have a coil I could try.

[38racing]

Replacement coil and carb intake spacer made no difference. It will start and just run slow with fully closed choke. Any movement of choke to open it begins to vibrate and stops. I've just reviewed info for doing intake center line on the valve . looks like near 105 atdc. Have to figure out mounting of degree .

[38racing]

Should have taken roym advice sooner. Since I had end cap off thinking about mounting degree wheel I decided to disconnect output (assuming input is from the brushes) from the avr module. Engine purrs like a kitten at 3600 rpm. What does that likely mean? Maybe now have to go down james Condon list of videos.

[Arkie]

Might be time to break out the electrical tester.
Noticed that Champion uses that same Model number for several different sizes of their KW gens, so if looking for rotor, stator and AVR specs the proper KW will need to be used. (one size won't fit all for ohms and AVR specs)
You might get lucky and just have a bad AVR. If it's a rotor or stator replacement price will be sadness.

Are you saying you unplugged the AVR?
If so it's time to try and determine if it's the AVR, the rotor, or the stator.
Just going from memory for couple of fast checks.
1. With the AVR disconnected check ohms brush to brush. Should not be very low, probably around 25 ohms to as much as 60. Look at the rotor windings carefully and the stator winding to see if you see any black or burned sections and sniff test.

2. To get an idea if the AVR is bad you can do a bypass test of the AVR.
With the AVR disconnected see if you can determine the polarity of the brushes plus and minus. (sometimes a + is stamped in the plastic by the brush holder)
If you can determine the brush polarity take a 12v battery with a 5 to 10 amp inline fuse and while the unit is running connect to the brushes with the proper polarity and see if the engine speed changes, If it changes drastically you have a bad rotor or stator.
If no change in engine speed check for a voltage output at the 120v receptacle for a low voltage maybe in vicinity of 25 to 50 volts AC. (some AC voltage)If no AC voltage a AVR will not fix the unit.
I think maybe them AVR's can be found for around $20 but may not be a bad AVR.

I cautioned before:
Do not leave the unit running in a fire hazard area and keep it away from flammable materials, especially when indicating a electrical issue. I've seen them rigs start electrical burning and spitting fire, sometimes after running for several minutes and continue to burn after the engine is killed. A fire ext handy is a good thing.

[Arkie]

This might be a owners manual and parts list for that model, (may have to use google or Yahoo browser instead of microsoft edge)
4kw peak
2880 nominal

https://y79961nbs4u2hvbnwronx9zx-wpengi ... nglish.pdf

[38racing]

Might be time to break out the electrical tester.
Noticed that Champion uses that same Model number for several different sizes of their KW gens, so if looking for rotor, stator and AVR specs the proper KW will need to be used. (one size won't fit all for ohms and AVR specs)
You might get lucky and just have a bad AVR. If it's a rotor or stator replacement price will be sadness.

Are you saying you unplugged the AVR?
If so it's time to try and determine if it's the AVR, the rotor, or the stator.
Just going from memory for couple of fast checks.
1. With the AVR disconnected check ohms brush to brush. Should not be very low, probably around 25 ohms to as much as 60. Look at the rotor windings carefully and the stator winding to see if you see any black or burned sections and sniff test.

2. To get an idea if the AVR is bad you can do a bypass test of the AVR.
With the AVR disconnected see if you can determine the polarity of the brushes plus and minus. (sometimes a + is stamped in the plastic by the brush holder)
If you can determine the brush polarity take a 12v battery with a 5 to 10 amp inline fuse and while the unit is running connect to the brushes with the proper polarity and see if the engine speed changes, If it changes drastically you have a bad rotor or stator.
If no change in engine speed check for a voltage output at the 120v receptacle for a low voltage maybe in vicinity of 25 to 50 volts AC. (some AC voltage)If no AC voltage a AVR will not fix the unit.
I think maybe them AVR's can be found for around $20 but may not be a bad AVR.

I cautioned before:
Do not leave the unit running in a fire hazard area and keep it away from flammable materials, especially when indicating a electrical issue. I've seen them rigs start electrical burning and spitting fire, sometimes after running for several minutes and continue to burn after the engine is killed. A fire ext handy is a good thing.

I'm seeing your suggestions also in a James condon youtube video. From his video I guess I have avr input/output wrong. I disconnected the plug ( 4 wires ?) and left it connected to the brushes. On his unit he says his .5 ohms across the receptacles indicates ok stator. He says his .75 ohms across the brushes is good. I'm showing 500 ohms across the brushes. He shows the battery on the brushes test but that's as far as I've watched. His problem is no output.

[Arkie]

I've not seen his video and never heard of such:
Rely on his info.
I'm just giving you basic testing procedures.
A link to his info might be helpful for us?
I've not searched for such.

.75 ohms brush to brush with the brushes isolated from the diodes or AVR seems too low and your 500 ohms brush to brush is normally too high.
Lift a brush and check slip ring to slip ring and then brush to brush ohms. Any difference will be the brush contact resistance. Slip ring to slip ring is the rotor resistance.
AND the .75 ohms mentioned is not a true test of the stator windings. The stator has multiple additional winding that can be shorted.
It appears to me that the engine is loaded up heavy due to a MAJOR overload taking place in the electrical section. (high current)

You might also try testing the Diodes that are just before the brushes if you can see such.
Check the front to back resistance ratio's. If one is shorted it can cause such because AC voltage would be fed to the rotor instead of DC. The battery test to the brushes I mentioned would be a hint of AVR or bad diodes if the engine operated ok using a battery as the rotor exciter.

Stay safe electrically.

Also make sure that no one has loosened or removed the long center rotor bolt.
The long rotor bolt (usually about a 5/16 diameter) holds the rotor press fitted to the tapered engine crankshaft. Never run the engine with this bolt loose or removed because the rotor is spinning at 3600 rpms and can do severe damage if it come off. (damage to you)
I also check and make sure that the outer rotor bearing (by the brushes) is ok and not seized and spinning in it's race. (rotor can vibrate due to such and come off the crankshaft)