Champion Generator not even close to rated output

[CapnCampn]

Continued from here:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29788443/gotomsg/29792553.cfm#29792553

I have a Champion Non-inverter 3500/4000W generator that isn't putting out it's rated output - I've tried running 2 1500W electric heaters on it, and it will bog down and die.

The Gen is model C46540

I did email Champion about the issue, and they had me run electrical checks on the generator side - everything seemed ok, so it appears to them (and me) that it's an engine/hp issue.

I'm at about 2500ft, and they say that the generator will be down about 300 watts at this altitude, so should sustain 3200 watts.
My testing was done with a kill-a-watt and various combos of hi/low settings on the heaters As BFL found, once you get a ways above 1500W, the kill-a-watt starts to complain. I think all the numbers in the table below were from the Kill-a-Watt.

I tested the output with a couple of electric heaters plugged into a power strip using the 5-20R receptacle (not the TT30).

This was at the end of a 40' 12Ga extension cord (it was raining a bit so I wanted to be under cover), using the Kill-a-Watt & combinations of 2 electric heaters with hi/lo settings.

Watts Volts Hz
21 119 64
750 117 61
1220 116 59
1370 116 59
1420 116 59
1930 115 58
2050 115 58
2330 113 56

At the 2300W range, the engine on the generator was working really hard, and starting to lug - you can see this in the frequency column. At one point, it was about to die, and the kill-a-watt actually reset. I turned off a heater before the engine died though.

I feel that this load shouldn't be a problem since it is only ~66% of the generator's rated output, and these are mostly resistive loads (both heaters have small fans of course).

The temp was ~60 degrees, and I am at 2700ft elevation.
I thought maybe it had something to do with using only the 5-20R, but the schematic in the manual shows that both 120V outlets are paralleled, so they should be able to provide the same power, limited by the receptacle specs. The engine/generator shouldn't care which one is being used.

From the engine side, the gas is not new, but has had stabilizer in it, and the oil only has about 2 hours on it. I think I adjusted the valves the spring before last, but I can’t remember for sure. The Spark arrester is clean.

I'm not sure what else to check at this point. Generally it does what I want it to do, but it's a little disappointing that it won't do at least 3KW.

[beachcomber_1]

Read all of comments , would suspect engine. if original owner abused it, things to check valve seats and valve lift. bad seats and worn cam can not be fixed by adjusting valves. sounds like original owner push it too long between maintenance.

[CJW8]

A new Carb for my CPE 4000/3500 cost a whopping $12 on Amazon. It restored my power and eliminated a hunting issue. I think I did this twice over 8 years of ownership. Not worth my time to tear down and clean for $12.

[glennts]

Not that I know anything about any of this but I have noticed that in all of the trouble shooting advice there was no mention of the heaters themselves being the problem. Is this even a possibility?

[CapnCampn]

A high altitude jet would make it run lean at lower altitudes.

I have no reason to believe the jet has been changed though. I didn't look for any markings on it when I pulled it out to clean it.

CC

[2112]

What would a high altitude jet in it do if you run it at the lower altitude where you are?

[72cougarxr7]

I have had the same generator for about 8 years.
It seems to have no issue putting out its rated output.
You can tell when it is on the upper end of its capacity there is a load on the engine, but it does not act like it is excessively laboring or on the verge of stalling.
One thing I will say, you may want to try a new spark plug.
I know it may sound silly, but I have had small engines that were doggy, and the spark plug looked fine, but a new one woke it right up.
Get an NGK B7ES.
I would be especially suspect it it still has its original made in China spark plug, they are known to sometimes be finicky.

Also if it has been sitting for some time and the gas in the tank is questionable, drain the tank and fill it with fresh gas. I try to find ethanol free gas for my small engines. Around here the only way to get ethanol free is go buy the 90 or 91 octane, so the cost is higher, but I have had no issues with cracking fuel lines or varnished or corroded carburetors since switching to ethanol free several years ago.

Edit: I just noticed you already posted you have ethanol free gas, so you are good to go on that!

[CapnCampn]

Lessee.. where were we?

In response to a recent question, yes it is an older generator that I got (at least) 2nd hand, so hours are unknown on it.

I used the thing this weekend, it ran a couple of crock pots ok. it didn't run out of gas (which I dumped some Techron in), so I didn't get a chance to try my can full of shiny new ethanol free 87 octane.

I don't have a twist lock anything to plug into the 240V side of the gen, so at the moment I've exhausted my testing options, and it's now really cold outside. So I think I'm done for a while.

It sounds like there may be an issue with the windings, but Chum Lee gave some other engine related tests to look at. Even if there is a winding issue, it's certainly not a doorstop. It's run everything I've NEEDED it to run so far, up to and including the AC on my trailer.

I have thoroughly enjoyed all the suggestions and banter so far, if I happen to try some other options, I'll report back.

Thanks to everyone!
CC

[Chum_lee]

CapnCampn wrote:


I have a Champion Non-inverter 3500/4000W generator that isn't putting out it's rated output - I've tried running 2 1500W electric heaters on it, and it will bog down and die.

The Gen is model C46540

I'm at about 2500ft, and they say that the generator will be down about 300 watts at this altitude, so should sustain 3200 watts.

Watts Volts Hz
21 119 64
750 117 61
1220 116 59
1370 116 59
1420 116 59
1930 115 58
2050 115 58
2330 113 56

At the 2300W range, the engine on the generator was working really hard, and starting to lug - you can see this in the frequency column. At one point, it was about to die, and the kill-a-watt actually reset. I turned off a heater before the engine died though.

I feel that this load shouldn't be a problem since it is only ~66% of the generator's rated output.

The temp was ~60 degrees, and I am at 2700ft elevation.

From the engine side, the gas is not new, but has had stabilizer in it, and the oil only has about 2 hours on it. I think I adjusted the valves the spring before last, but I can’t remember for sure. The Spark arrester is clean.

I'm not sure what else to check at this point. Generally it does what I want it to do, but it's a little disappointing that it won't do at least 3KW.

Clearly you are getting to the correct Hz (+-60Hz) so the governor is working at no/low loads but the genny is losing power (RPM) as it tries to load up.

Use fresh gasoline with no additives. Then:

Have you checked the engine static compression? Have you checked the engine spark timing? Have you checked for vacuum leaks? Have you checked the crankcase breather function? Any of those singly or in combination would explain the engines inability to generate rated horsepower @ RPM and ultimately the rated wattage.

The Champion tech team correctly advised you of the expected power loss because of your elevation above sea level and ambient temperature.

Chum lee

[KM_Rolling]

I have the same generator. Will pull a 3500 watt load all day long, no issues.

Sorry for the troubles you're having.

I have not read thru all the pages, but what you describe sounds like starving for fuel.

I am not near mine right now, but there must be some sort of fuel filter or screen...possibly that is restricting the flow of fuel when more is demanded from the heavier load?

[bg71361]

Update from the OP??

[Gdetrailer]

road-runner wrote:

Gdetrailer wrote:

Not sure why these two things got your shorts all bunched up, I basically laid out for free how to figure out if the problem is a shorted winding or not and have given lots of good free advice the OP can use to determine if it is fixable or if it is a doorstop..

Since my shorts are all bunched up, I'll point out that you apparently didn't notice I posted the same free advice a bit over two hours before your post, and I read the manual first to avoid the wrong advice that the 120 volt outlets are active in 240 volt mode.

:R

I didn't "give" any "wrong" advice, OP SHOULD ALREADY KNOW AND UNDERSTAND that the gen turned off the 120V outlets and should not have "needed" your "sage" advice while blasting me..

OP OBVIOUSLY UNDERSTOOD EXACTLY WHAT I MEANT BY TAKING THE SEPARATE VOLTAGE READINGS (they DID figure out how to do that).

Doesn't take a rocket scientist or brain surgeon to figure out just how to hook up two separate heaters on two separate windings from the 240/120 twist lock..

Getting blasted around here is a normal routine any more and is why folks have quit posting.. Guess I will have to put you on the ignore list, not many have made it this fast..

Carry on..

[2112]

And it had to turn to this! It was fun while it lasted.
Good Luck OP

[road-runner]

Gdetrailer wrote:

Not sure why these two things got your shorts all bunched up, I basically laid out for free how to figure out if the problem is a shorted winding or not and have given lots of good free advice the OP can use to determine if it is fixable or if it is a doorstop..

Since my shorts are all bunched up, I'll point out that you apparently didn't notice I posted the same free advice a bit over two hours before your post, and I read the manual first to avoid the wrong advice that the 120 volt outlets are active in 240 volt mode.

[MrWizard]

i did read the first post, but forgot the info so i stand crrected on 'that' matter,
and i'm correct, about the age , that model is close to ten years ago on the introduction date, and yes it was mfg and sold for several years

did he buy it new ? has it been used or stored ?
did he buy it used ?, how many hours on it ?
could be age and wear

he can run one on high and one on low, but can't run both on high
which total 2920va, when testing each one and adding them together

new that model should run both heaters

but it is NOT running like new, Not Now

given that the engine runs to a certain power level
and is not affected by the addition of more fuel
seems to indicate carbon build up in the cylinder head

many years ago i bought a dodge 6cylinder engine that acted like that
(actually a garage in Tenn installed in my van)
purred like a kitten, started like a dream, ran smooth as silk, would not drive over 45mph

they made good, the pulled it and replaced it with another engine

it is a possibility to be considered