My Snapper Lawn Mower stopped working due to bad Pemex gas I brought back and poured into its tank last month. My next step will be to fill it with a high-quality gasoline and see if I can start it up.
The symptoms? It stumbles, but will not start. The last time it ran, it sputtered for about 3 minutes, and would not start again. Any Nomads ever
encounter this with your Gardening equipment?Maderita - 5-6-2013 at 02:40 AM
Your description is thin on diagnostic info.
Nevertheless, here's my take:
Don't be so quick to assume that it has anything to do with "Pemex gas."
The problem is likely fuel and/or carburetor related, but due to old gas and "varnish" deposits.
It is very common problem on small engines (motorcycles, ATVs, generators, gas water pumps, lawnmowers, chainsaws, etc.) The underlying problem is
twofold.
1. They tend to sit for weeks/months/years without being run. When they are run, the tank may be partially used, so all or most of the gas in the tank
may be quite old. Old gas separates and the varnishes form gooey solids (varnish).
2. The carburetor fuel bowl is small. The fuel bowl venting is likely not a closed system, instead venting through a tube to the outside air. The
residual gas in the bowl can evaporate completely, leaving behind a coating of varnish deposits.
Gasoline refiners save money by skimping on the stabilizing chemicals. Consequently, gas is only "fresh" for a few weeks. I consider 6 months to be
the outside limit without adding a stabilizer.
Your mower engine symptoms sound like a gummed up carb. (caveat: I don't know anything specifically about Snapper mowers).
Either the main jets are clogged or the float in the fuel bowl is stuck. Stuck in the up position, the float will close the inlet valve, not letting
fuel into the bowl. Stuck in the down position will overfill the bowl, causing flooding (excess fuel in the cylinder).
When you say it "stumbles" are you saying it will fire a few times like it is trying to start, but not keep running? If you get a cloud of black smoke
out the exhaust and smell raw fuel, then it is flooded. Hold the throttle wide open, with zero choke, and crank the motor several times.
If there is no black smoke and no smell of gasoline, then it may not be getting enough gas. Pour a half teaspoon of gasoline, or a quick shot of
Berryman B-12 Chemtool or Gumout (or use the more volatile spray ether aka : "quick start") down the carb and see if it will fire off. If it runs a
few seconds then dies, you have narrowed it down to a fuel delivery problem (vs. ignition or compression problem).
If you get it to run, try stalling it by covering the bore of the carb (real men use the palm of their hand, but for safety try a rag) to cut off all
of the air. The idea is that it creates a strong vacuum to suck particles trough the jets and passages.
If it doesn't fire off, check to make sure that you have a strong spark. I doubt that is the problem, however, it should be ruled out before
disassembling the carb.
A stuck float is often unstuck by tapping on the side of the fuel bowl. I prefer to use the hard plastic handle of a screwdriver. You don't want to
overdo it with a hammer on cast aluminum. That may only be a temporary solution, as the varnishes that caused it to stick have not been removed from
the carb.
Next, try removing the fuel line from the carb. Good time to make sure that there is no obstruction and that fuel is actually flowing out of the tank
and into the carb. If gas isn't flowing, check an inline fuel filter or pickup screen in the tank outlet. Squirt Chemtool / Gumout directly into the
carb and let it sit in the bowl for a few minutes. Sometimes that will do the trick if the varnish problem is mild.
If all of those measures fail, you will need to remove the fuel bowl from the carburetor. Use care as there may be a spring or two, incl. one on the
inlet valve. Pull straight off so as not to bump the float out of adjustment.
Clean everything well. I use a stiff toothbrush or small parts brush and Chemtool. Spray all of the holes and jets using the thin red "straw" found on
the side of the can. A severely clogged jet might require reaming with a wire.
It should run good-as-new when you reassemble. Next, you will want to prevent this from happening again:
If you aren't using an entire tank of gas and it will be sitting for more than 3 or 4 months, then empty the tank. Alternatively, you might try a
gasoline stabilizer, Stabil or Seafoam, for storage supposedly up to a year.
Shut off the fuel between the tank and carb, hopefully there is a petc-ck on the bottom of the tank. If not, install an inline petc-ck. After every
use, close the petc-ck and then run the engine until it starves and dies. Takes 15 seconds to a minute. Increase the throttle as it starts to starve
and slow in rpm's).
I get lots of practice with this between desert seasons. The buggy with dual Delorto carbs, a Honda generator, and dirt bikes sit unused for 6 or 7
months. I run all of the carbs dry, then dispose of the leftover fuel in the generator and bikes, and add stabilizer to the buggy's tank. There is
never a problem. You should see what my friends go through at the start of a new season! A little prevention saves hours of frustration.woody with a view - 5-6-2013 at 03:21 AM
spark plug.chuckie - 5-6-2013 at 03:59 AM
not the gasnbacc - 5-6-2013 at 05:24 AM
I go to Baja so I don't have to mowBob and Susan - 5-6-2013 at 05:52 AM
its probably just a dirty carb and a stuck float
but
it could be gas in the oil
on small engines...if it sits for along time...
sometimes gas seeps past the rings
check the oil level...if it high or too thin just change it
an easy fix
I never run the thing out of gas...its better to start it once in a while
if you run it dry ...for sure...you'll be cleaning the carb
edit: remember where that Pemex gas was refined...you know
[Edited on 5-6-2013 by Bob and Susan]Marinero - 5-6-2013 at 06:39 AM
What is a "Lawn Mower"?JAG - 5-6-2013 at 07:08 AM
Check the air filter and cleanabsinvestor - 5-6-2013 at 08:03 AM
I agree with Maderita. Same thing has happened to me twice. Last year I had the lawn mower tuned up, blade sharpened etc etc. Worked perfect. Last
week I pulled it out of the storage shed. It started but spit, sputtered etc. I knew since I had just had it tuned that it must be the gas. I drained
the gas in the tank (US gas), poured out the little gas that was left in the gas station and headed to the gas station. I put the new gas in the
mower, pulled the cord and it ran like top. I would also mention that a few years ago I had the same problem with a new weed eater. A brand new
weedeater wouldn't start. When I took it back to Lowes where I had bought it the guy asked me if I had old gas. I told him the gas was fine but it was
gas from the prior year. He told me to dump out the gas, add new gas and if it didn't start he would give me a new weedeater and a $20 coupon for a
future purchase. I changed the gas and the weedeater immediately started.durrelllrobert - 5-6-2013 at 08:13 AM
Maybe it's just the altitude. Try raising it a little at a time until it runs right:
Udo - 5-6-2013 at 08:41 AM
Ken:
Drain the old gas, put in new gas, I am sure you can find some VP racing gas.
Fill the tank about 1/2 full, add a 1/2 pint of acetone and a 1/2 pint of rubbing alcohol. (acetone clears up varnish & alcohol mixes with gas to
eliminate stalling from water). Run the engine until it runs out of gas.
Those two should clear up the varnish.
If That, by chance doesn't clear it up, I can meet you somewhere and bring you a can of professional gas additive that my company sells. It is about
$20,00 a bottle, but it's claim de fame is that it clears up check engine lights and guarantees that you'll pass smog after you add a bottle.
It has cleared up my light on my Prius which now has 488,000 miles.TecateRay - 5-6-2013 at 08:52 AM
The ethanol added to all US gas increases the problem of "old" fuel in small engines. It also rots out o-rings and other rubber and plastic parts,
causing fuel issues due to particles clogging jets, etc.
This is a well known problem with motorcycles and since I am a frequent rider in Baja I have learned a few lessons on the topic.
First of all, most gasoline in northern Baja is refined in the US. Gas doesn't sit around in the tanks at stations in Baja like years ago either.
A friend who is a materials engineer checked a sample of PEMEX premium a few months ago to see if it has ethanol - the answer is no! I try to run
only PEMEX Premium in my bike now to avoid fuel problems. I also do the trick mentioned above by turning of the fuel petc-ck and running the bike
until it quits. This still leaves a little in the float bowl, but not much and usually not enough to coat the jets with varnish if it sits too long.Wally - 5-6-2013 at 09:32 AM
Seafoam, seafoam seafoamBob and Susan - 5-6-2013 at 10:29 AM
never put rubbing alcohol in your gas tank...it'll eat rubber
and there is no cure for the commom cold either and
there no chemical additive that will pass a California smog inspection test
by adding to the gas tank
another urban myth...
Carb
J.P. - 5-6-2013 at 11:21 AM
OLD Biker Trick. Disasembel it And place it in a small pan and add water and a small amount of dishwashing soap. Bring to a boil then empty pan and
rinse the Carb and parts will be shinney like new. Reasemble and adjust. it will run like new.EnsenadaDr - 5-6-2013 at 12:01 PM
you mean the water pump they use to charge customers and then pocket the money?
Throw it away
bajaguy - 5-6-2013 at 01:05 PM
if it's a Snapper, throw it away and get a HondaDENNIS - 5-6-2013 at 01:13 PM
Buy some Paraquat, kill what's left of the grass, throw the mower in the trash and go get drunk to celebrate a good day's work.TMW - 5-6-2013 at 02:45 PM
Help the economy and hire a lawn service.chuckie - 5-6-2013 at 03:23 PM
I had a date ruined once, by excess gas....monoloco - 5-6-2013 at 04:17 PM
Quote:
It has cleared up my light on my Prius which now has 488,000 miles.
Impressive, that's a lot of miles for
any vehicle. Original batteries? Any major repairs?motoged - 5-6-2013 at 04:24 PM
Quote:
Quote:
[
Impressive, that's a lot of miles for any vehicle. Original batteries? Any major repairs?
Ah, great. Finally a thread hijack to liven things up.
And what about Mark and whatshername moving away from their restaurant.....
Did they really move to Central America ? ....lower cost of living....Ecuador (SA) is really being touted as an inexpensive place to live. Has
anybody any current experience with Ecuador?
DENNIS - 5-6-2013 at 04:24 PM
Quote:
Originally posted by Udo
It has cleared up my light on my Prius which now has 488,000 miles.
I use black tape for that. Ken Cooke - 5-6-2013 at 07:34 PM
Quote:
Originally posted by TW
Help the economy and hire a lawn service.
I did...temporarily. I hired the lawn service's onetime half-owner to trim cactii in my yard, and he cut his finger w/a chainsaw. I gave him a nice
tip, and stopped using the service. Now, several years later I am back, but only as long as I have to since accidents can and do happen.CortezBlue - 5-6-2013 at 07:38 PM
Originally posted by Ken Cooke
.....he cut his finger w/a chainsaw. I gave him a nice tip....
Like what? The end of his finger???DavidE - 5-7-2013 at 09:32 AM
CORTADOR de CESPED MEXICANO
Trick learned from professional loggers. Drain tank. Run 'till quits. Put in a half quart of WHITE GAS. Start, run 15 seconds shut off. White
gas can not go bad, ever. No gum no varnish. Have stored stuff five years, starts instantly.
White gas....
neilm81301 - 5-7-2013 at 09:36 AM
can be a little hard to find these days. How about Coleman fuel?
NeilDavid K - 5-7-2013 at 10:20 AM
White gas is simply unleaded gasoline (but without automotive additives), and Coleman Fuel is White gas.Ken Cooke - 5-7-2013 at 09:26 PM
Quote:
Originally posted by motoged
Quote:
Originally posted by Ken Cooke
.....he cut his finger w/a chainsaw. I gave him a nice tip....
Like what? The end of his finger???
He didn't need stitches...phew!Frank - 5-7-2013 at 11:09 PM
"Naphtha is used primarily as feedstock for producing high octane gasoline (via the catalytic reforming process). It is also used in the bitumen
mining industry as a diluent, the petrochemical industry for producing olefins in steam crackers, and the chemical industry for solvent (cleaning)
applications. Common products made with it include lighter fluid, fuel for camp stoves, and some cleaning solvents. Light Naphtha is also used
directly as a blending component in the production of gasoline."
Replacing 100% fuel in equipment for storage with white gas is 10-times better than trying to use an additive to inhibit the formation of gum and
varnishes. I've had the "best" gasolines with Sta-Bil go bad, and name any other storage additive including Sea Foam. Draining and Replacing with
COLEMAN FUEL is so much better it is laughable. This includes generators used seasonally in Mexico and motorhomes. A customer started a 6.5 NH Onan
genset stores TEN YEARS, and he chortled it started "Instantly".
Pemex Gas
wornout - 5-8-2013 at 09:14 PM
I have been using Pemex gas in San Felipe in my leaf (sand) blower, power washer (for a lot of sand), and Honda generator for years with no problems.
In fact, when we go to San Diego, I make it a point to fill up in Mexicali so I don't have to buy gas in California.
My next step will be to fill it with a high-quality gasoline and see if I can start it up. 
