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Picked up a Champion Porta Champ air compressor at an estate sale today. Serial #212938, Model #FM10G. I can find no info on it. It has a gas engine that appears to be a Briggs & Stratton, and a single stage compressor. Maybe a 1960-70 vintage compressor. 15-20 gal tank. The engine has compression and spark and no rust in the tank. It hasn't been used in a very long time. Any info help from you folks would be appreciated. I'm going to disconnect the drive belt and see if I can get the engine to run, then check into the compressor.

Rick

Being that old, check the inside of the air tank for rust.
You wouldn't want it to blow on you!

Don

Old B&S engines, the ones made before electronic ignition, are notorious for getting oxidation on the ignition points if they're not run regularly. Pull the flywheel and burnish the points with a clean pencil eraser- - - -it has just enough abrasive to polish the contacts without leaving deep scratches. Then loosen the attaching screws for the ignition coil and use a 3X5 index card to set the gap between the coil and the flywheel magnet. Set the point gap (I think it's .020") and button everything up. That aluminum flywheel timing key is made of soft metal for a reason- - - - -don't get tempted to replace it with a steel key. Do all the above, and you'll have a hot spark that happens at even very low cranking speeds. You can pull the spark plug and spin the flywheel by hand and still get a good spark.
Jerry

Also check the pickup tube and screen. You'll have to separate the gas tank from the carb to do this but I've found many that were clogged or plugged...particularly if they've been sitting for a while and especially if they were the 5hp model. If you put a bit of gas in the spark plug hole, replace the plug and it starts when you crank (or tries to start), it is a good indication you're not getting gas through the carburetor.

That's particularly true if a partial tank of "deathanol" added gasoline was allowed to sit and evaporate after the final run of the engine. That white powdery residue has spelled the demise of a lot of carburetors. I've got a very nice belt-driven compressor on a tank with a hole rusted into it. It's about to get adapted to a retired 100-lb. LP gas cylinder that's out of date on inspection, and the gas vendors refuse to fill. Those tanks are far heavier and stronger than the ones used for compressed air. I'll have to do a little creative plumbing to create a way to drain condensation, but that's not a big deal.
Jerry

Find and attach a weld-on bung?

Update

The engine has great spark. Runs with gas dumped into the carb then dies. Replaced the fuel line, it was so brittle it broke off. Put some gas in the tank and it would not run. Gas makes it to the carb and no further. Took the carb off and disassembled. Stuck needle and seat. Very little crude in the carb. In the process of making a new gasket for it. I noticed there is no needle adjustment screw on the idle mixture hole on the side of the carb to adjust for idle mixture. Is this normal for a gas engine air compressor? There is no throttle on this engine. It is set up to run a constant fast rpm.

Rick

No throttle? It must be governed somehow so as to not explode if running unloaded.

It has an adjustable rod that keeps the throttle in a fixed position. There is also a spring loaded governor.

Rick

I see, it does have a throttle but no easy manual control of it. Thanks for the clarification.

Update II

Reassembled the carburetor after making a gasket for it. Engine runs great. Going to go thru the air compressor next.

Rick

Update III

Could only get 50 psi when running. Too many rust holes in one end of the bottom of the tank. Cut out the rusted area and welded in new steel. It has a 100 psi unloader valve. It will put out the required 100 psi and the unloader valve will maintain it at that pressure.

Rick

You should invest in a new tank, or a good accident insurance policy. There's a reason there are certified "pressure vessel" welders. Patching on an air compressor tank ranks right up there with sewing up rips in a parachute.

Search youtube for exploding compressor tanks if you want a reference as to what your risks are with using a patched tank. The results are not pretty.
I try to fix just about everything which is broken. Not air compressor tanks.

Gents, that has been my intent to find another tank if the rest of unit was OK. Did not want to invest in a tank if the rest of the unit was junk. I find your advice very valid.

Rick

That one test run probably used up all your luck for quite a while. Don't bother buying any Powerball tickets for a year or three!
Jerry

So Jerry ... Would welding a patch in a fuel tank be bad, too, then???

I wonder who was in charge of the safety committee that day?? Possibly with the initials of ..... J.M? And he can't even say he wasn't there to witness it, he was taking the picture

Man, I see you can't expect a break from this crowd! My guess is the tank was full of water or more likely inert gas (not gasoline for sure). But then I'm just guessing

Added in edit:

Not that most would go to the trouble, but if you did want to test a pressure vessel (air tank) the safe thing to do is fill it with water and take the pressure up to 1 1/2 times the operating pressure, let it set for hour or so. Fact is I'm not really comfortable mentioning exact "how to info" since a very detailed set of steps are required as detailed in ASME specs that Mr. Google can provide. Suffice to say, if one runs enough temporary black pipe so the vessel/tank can be pressured up from a safe distance and location (this includes the montoring pressure gauge) then it's a much safer thing than just letting the air compressor do it's job while you stand there and watch. Hydrostatic (pressurized water) testing is a MUCH safer way to test when compared to pneumatic (nitrogen or air).

I've welded a bunch of fuel tanks- - - -even did a braze fix of a fuel fitting leak on top of one about half full of gas one day. The trick is to totally fill the interior of the tank with a non-flammable gas like nitrogen, CO2, or even exhaust gas from a very rich-running engine. No oxygen to support combustion- - - - -no kaboom. Pressure vessels don't have to have a fire to do damage- - - -the fracturing of the metal itself is the dangerous part.
Jerry

Safety Committee??? We don't need no stinking safety committees!

I haven't welded a fuel tank, but I supervised welding one from a gasoline engine M88 tank recovery vehicle (probably over 100 gal capacity). We filled it with water nearly to the level of the crack that needed welding, then discharged 2 CO2 extinguishers in it. When the welder touched the arc, it gave a little "boomp", at which point I told him to keep welding, as all the fuel had been consumed.
The problem with air tests on tanks or piping is that the air is compressible and thus stores energy. Water (hydrostatic test) on the other hand is incompressible, and the only energy stored is in the slight flexibility in the tank steel itself. Any rupture of the tank reduces the pressure nearly immediately, so no explosion.
Overheated water heaters, developing steam inside, however, can turn into rockets, and have destroyed housed in the process of exploding. Mythbusters did a video of one where they plugged the relief valve and let it cook. It took off and flew about 100 ft in the air thru two floors of the test house they had it in. Didn't find that one, but here's a video of one they did out in the open. Water Heater Rocket Pretty exciting, but sobering too if you think about the damage it could cause.

Can we start a new competition similar to chunkin pumpkins?

I- - - -errr- - - - -a "friend'" used to have fun with a length of water pipe, hair spray, and tennis balls. The cops got called on a regular basis in "his" neighborhood about somebody setting off bombs!
LOL!
Jerry

Jerry, I once knew a guy.....used potatoes and hair spray and 3" PVC sch. 80 pipe to create diversions on hot summer days when more like minded juvenile old guys would gather to enjoy beverages shoot the bull,,,,er spud.

You just need to know when to jump out of the way...
Notice the mountain lion-like way this gentleman has positioned his rear legs. Ready to pounce instantly right out of danger's way.

klhansen, good summery concerning hydro vs pneumatic testing and the dangers. My last pipeline project (I sorta retired/kinda in '15) we used nitrogen to test 30 mile sections of 16". A less than capable contractor let ditch water freeze in the pipe by not back filling trench at tie-ins. This caused a major problem (in sub zero degree weather) in clearing the ice so the line could be pigged prior to testing. Then the company construction VP was convinced water was bad, nitrogen was good. As project manager I could not change his mind, so we tested with nitrogen. The spread was 2050 psig to 2225 psig. I was definitely one nervous country boy while on test. I promised the wife I would not get within 300' of "on test pipe". Of course that didn't work but thankfully all went according to plan.

Always use water to pressure test!!