4200 coleman generator, burns oil it also makes loud popping sounds about 10-30 minutes into use. maybe backfiring sound? Im not used to the backfiring sounds so Im sure thats what it is, but it uses allot of oil. Is there a rebuild kit maybe and a free manual online somewhere? Cant afford small engine repair as I got it cheap and cheap is in my budget. Thanks much for your help in advance PM0524208 , coleman powermate 4200

Not enough information to answer. Need manufacturer, year, model, and engine size in order to answer the question.

What does the oil look and smell like? Also what conditions is it been ran in lately, and what fuel are you running?

The most common cause of back firing is un-burned gasoline in the cylinder. Make sure your air filter is clean and there are no spider webs in the air-intake manafold. Also, be sure your spark plug is clean (new). Finally, check that the spark plug wire is not damaged/cracked. Each of these can allow excess fuel to exist in the cylinder and cause back firing. This process does not always occur in the cylinder. Fuel can also build up in the muffler and burns/explodes once the muffler gets hot enough (but that is rare on such a small engine with a muffler that gets as hot as your generator should).

Another issue is carbon buildup. This hot soot (carbon) on the piston and cylinder head to store heat from previous combustion cycles of the engine. This carbon eventually gets so hot that it can ignite the fuel/air mixture entering the cylinder BEFORE the spark plug ignites it. Having that fuel mixture explode when the exhaust valve is still closed makes the engine hemmorage and make strage noises once the exhaust valves to open. This is called pre-ignition. It is not as loud as a backfire but it is loud.

In summary, clean your air filter, and air box, and have the carburator adjusted back to factory specs (if anyone tried to turn any screws on the carburator since it was new). If the unit has not been used much, it is likely the air filter. If it has been used heavily, then the soot/carbon build up is likely an issue.

Sounds like you may have oil in the cylinder. This is caused by engine tipping over or maybe the generator fell over on its side, etc. This ends up making it really hard to pull start the engine.

Anyway, try removing the spark plug (make sure the ignition wire is pulled out of the way) and then turn over the engine a few times (5 or 6 times) to get any oil out.

Then replace the spark plug and try again to see if it starts.

I get the same sound but I found it is actually coming from my stainless steel backsplash, it seems like the heat makes it flex from time to time.

I have an HM100 on a 5500 watt gen with the same problem. This motor calls for a J17 spark plug, but I found using a J19 (hotter) plug solved the problem. I think the J17 doesn't get hot enough for a complete combustion burn so it act like fuel starvation thus resulting in the black sooty and wet plug.

you have either water in the fuel, or you have a plugged catalytic convertor

As silly as this is going to sound, make sure the oil level is right. I have a Powermate 6250 that did the same thing to me. Turned out the oil was just a little too low and the sensor was killing the power. When you try to start it, the red light will be flashing in the on/off switch, that's the low oil indicator. Hope this helps.

the carby needs to be cleaned out properly the jets blown out with air.when you intendto stop useing for any length of time swich the fuel off and let itstop by running out of gas or drain the carby before storage ,as fuel evaporates and the additives dont they build upafter a while and start to block the jets make sure motor is level,oil cutoutcan be fooled if not level ,disconectwire if worried about that bing the problem

Wow, you've got an ugly problem. It sounds like you already know that you have to pretty much disassemble these little buggers down to the frame to see anything inside, so I'll say what to look for:

1 - Burned wires in the part of the generator that doesn't move. This is the bit that carries the current shorted out by the mud.

2 - Burned wires in the part that does move. This is the bit that makes the magnetism that makes the electricity. There are also some diodes and MOVs tucked into the end of the plastic insulator

You're likley better off getting some other generator, sorry.