Hi out there fellow generator people, trysquie in South West Pennsylvania here. I have a Coleman Powermate 5000W 6250W peak generator with the Tecumseh 10 HP motor (after reading the site I wish it was a B&S motor). I have talked to a teck who works on these units and he told me that I should use straight 30 W oil. He said that when people use multi grade they blow up. I asked him what he thought about Castrol straight 30 weight. He said that is the good stuf. He also said the exhaust has female threads for npt pipe, if you remove the factory muffler you can get to the threads, and I could add my own muffler on this type of pipe. He also said to be sure to use a flexable conection on the pipe. I went on "McMaster Carr" site and found flexable stainless pipe (the lower cost unit is discontinued but if you order it they give you the higher cost higher quality unit at the lower cost). You will require some straight threaded pipe and some right angles. I found a small muffler with a heat shield at the local auto parts store (advance auto parts her in PA there part no. from the side of this muffler 18677 9 245 ) and used PC7 epoxt puty to temporally hold the corect mounting angles with respect to the muffler heat shield attaching to U shaped steel bent from 1 inch flat steel that I purched from home depo and bent into two big U shapes to mount to the bolts on the alternator (I had to put longer bolts on that side of the generator, and extend and move the ground wire to the other side of the generator). I used very long flexable hose clamps from NAPA, (two sets, each made of two of the longest they sell) to hold the muffler to the steel while the PC7 epoxy putty dried. After the epoxy cured I had a local auto shop weld the steel to the heat shield (make sure to ask them to be careful not to burn through the muffler when welding to the heat shield). I have a lathe so I was able to turn a piece of steel to make the cup shaped piece that I had welded to the end of the pipe and provide fit to the inside of the input pipe for the muffler. I now have a home made auto muffler adapted to this generator. It did reduce the noise considerably but the valve train, piston, and air intake still make quite a racket. Before it was louder than a gas lawn mower. Now it is not as loud as a gas lawn mower. The way I added this muffler it moves with the generator and motor but still has the flex pipe for extra give. I am now going to add a heat shield between the heat shield of the muffler and the generator for added protection of the generator. I e-mailed Amsoil about oil for these air cooled motors and they e-mailed me back and said that regular multi grade oil will break down and not provide protection in these motors. They said full synthetic multigrade can handle these motors and will not break down. They make a multi-grade 10 W30 SAE 30 specifically for small air cooled motors (and no, I am not an Amsoil dealer or in any way conected to them, or to McMaster Carr, NAPA or advance auto parts). You still have to change the oil every 25 hours of use. I have learned some things from your web site, and just wanted to pass on some of the things I have learned regarding generators. I use to be around boats and saw many ways that people can blow things up or make mistakes that cause big problems. I hope to learn enough from this site and others to keep my generator runing when required. Signed, trysqqire in S.W. PA

So, for the folks who are running their central AC on a small generator, there are some things to consider so you don’t damage your ac. Just because it’s working doesn’t mean it’s not harming your central ac. 1st you need to have a quick reading voltage meter your typical cheapie can’t read ms long voltage changes. What your looking for is when your ac starts what is the instantaneous voltage drop. If your seeing under 208V when starting your ac, your accelerating wear on your motor windings on the compressor. Your compressor takes a certain amount of wattage which varies depending on temperature. If your ac says 90lra at 208v you need 18,720 starting watts, to start the ac without a voltage drop. If your generator can’t supply the needed power, you’ll slow the engine down and bog the generator causing its output voltage to drop, and say it’s outputting only 185v starting the ac. That means your ac is now drawing 18720/185=101 amps, and for a longer period of time. at low voltage the ac will take longer to start, heating the motor winding on your ac significantly more, once the insulation degrade or the wiring melts in the ac your compressor is done, So it’s not that it can’t be done, but it will wear your compressor a lot more quickly. Also if your ac doesnt sound the same while running it’s because the motor is vibrating more due to a highly distorted ac wave form or high THD from the generator. This extra vibration will wear the compressor more quickly and if bad enough destroy the motor. So some things to keep in mind when running a central ac on a generator. something highly recommended for small generators is leave the ac running all the time to reduce starts which damage the motors and or install a soft start kit to reduce LRA. If the ac is noisy on generator power get a different generator with a low thd, make sure it’s grounded properly if needed and consider upgrading your ac run capacitor to a 440v. Real bottom line, a cheap generator can run a very expensive ac. But if it kills your ac you didn’t really save money by buying a cheap generator.

I'm going to respond to you since no one has. I've lived in SW Florida for 20 yrs and have gone thru many hurricanes. This last one, Irene took our power and water out. We get water form the local water co on the island and after a while the water stopped as well. They use brackish well water and do a reverse osmosis. When their power went out, so did our water. We always packe the refrigerator with food, canned goods anything before the hurricane and cool it a notch or so down. The fuller it is, the longer things stay cool. We run a generator with gasoline. we would run it here and there to keep the freezers going and concerve fuel. Not knowing how long we would be without power and without power the gas pumps don't work. All generators will handle X number of items, if you plug too many things in, they can't handle it. Howevere, as it generates electricity, there could be excess power just being wasted. So you learn what it can handle. I know a neighbor down the street from us had a propane tank that was connected so when the power went out, it automatically kicked in and in a safe way (it can be unsafe and can kill the electrical workers working on fixing downed lines). Your electrician should know how to wire things up. We hook up our generator and turn the main power off. It's safe for anyone working on restoring the lines but we don't know when the power actually comes back. We listen the the stillness know that the neighbors has automatically shut off:)) A 250 gal propane tank is HUGE. I would guess you could run on that for a very long time. If when it happens, take a reading of the tank, run what you want for a day and take another reading. It should give you a rough idea of the useage per hr or per day. While you may want to run your well pump, it's also a very good idea to have large containers of water handy. We have those large blue plastic containers for water and the red ones for gasoline. Water is the most precious and is missed the most during difficult times. It's also ideal to have a gas cook top or rangetop that can be lit with a match. I hope this helps you a bit in planning for the worst. Hurricane season is not far away. Semper Paratus as my latin teacher said. "always ready." Inga

Update; I did order an Automatic Voltage regulator and it did appear to solve the problem. FYI the regulator instructions said to set engine speed to create 62-62.5 Hz and I did so. That created 116 volts. BTW: before I replaced the regulator, I fired the generator up one last time to reset the speed to generate ~143 volts. However, this time the regulator was completely out of control with voltage all over the place. Fortunately after apparent successful replacement, I also found a country repair shop that works on portable gensets like mine (the more known shops only work on drive behind size portables). They kept it for a couple days (they were supposedly busy) and checked it out, told me it was fine and didn't charge me! I sure never realized or heard of a generator running high before. Sounds like it could happen to others and there is no way to know in advance.