Mower rained on won't start. ( Make, model tag missing)

[zxcvbob]

Cracked (and wet) ignition wire, or wet points, or wet paper air cleaner.

Bob

[Duane Bozarth]

Or, depending on vintage, wet ignition module or other...

I'm curious how you know spark plug "works" but don't have spark???

If they get wet and have cracked insulator or seal around base, they'll never dry out and work right again...I'd replace it on general principles--at least stick a different one on the end of the wiyur and make sure I'm getting spark before going further...

[zxcvbob]

Could also be just a little bit of water in the carburator bowl. I've had that happen a few times. I remove the jet in the bottom of the carburator bowl (tecumsuh engine) and drain about an ounce of gas out, and blow in the jet to clear it since I have it out anyway.

Bob

[Duane Bozarth]

zxcvbob wrote: ....

But he said he had "no spark", so fuel isn't the problem (yet) anyway...may be an issue he's got spark, granted...

[Tim Zimmerman]

Recently someone left our mower outside in the rain and it just wouldn't start. No spark. Spark plug works. I'd took apart the carburator and nothing seems to be blocking the fuel supply.

The grass is growing to my waist as I type. We are thinking of buying the same make and model which is on sale. I believe Honda makes better movers but we need a mower with power wheels and corner cutting blades. We have no options but to get the same old new one. What is causing it not to start?

Thanks

[effi]

gas caps on lawnmowers have small vent holes in them

rain water gets in through those holes

remember: gasoline is explosive, be extremely safe with it and around it

dump out all your gasoline in the tank, into a safe container and dispose of it properly, even a little water screws up your gas

crank the gas out of your carburetor/engine (full open throttle, pull starting rope or use electric start)

put some fresh gasoline in the tank

start it up

if it still won't start, carb jets need working over probably if it's gettin spark (may have dried gas/varnish that needs to be cleaned out)

get someone qualified to do this if you aren't

[Stormin Mormon]

Best guess would be wet wires in the high voltage ignition section. How about bring it indoors till it dries? Or squirt spark plug wire with a bit of "wire drier" from the auto parts store.

As the other fellow suggested, perhaps wet air filter.

I'd be tempted to give it a day indoors before going out and buying another one. Air conditioning and dehumidifier are a good idea, to supply it with some dry air.

[fundies sux]

Check to see if you have a spark by pulling the plug, attach it to the wire, pull the cord, and look for a spark

..For a quicker response, ask your wife or a neighbor to hold the plug while you test it

I spray a bit of Berryman's B-12 carb cleaner down the throat when starting mine up (takes 3-4 pulls max)

Ken

[Duane Bozarth]

effi wrote: ...

OP said and ..."it just wouldn't start. No spark."...

Gas ain't the problem (yet) anyway...

[effi]

op said "Spark plug works."

confused yet?

[zxcvbob]

He also said the sparkplug works. How does he know? Think about it.

Bob

[Duane Bozarth]

If you read my initial post I asked the same question...and I note he did answer it here as well...

[Duane Bozarth]

Magneto systems were used exclusively for a long time...

If it ran before it got wet it's highly likely it's moisture somewhere in the electrical system...if it didn't, then it's possibly the coil itself...

[Tim Zimmerman]

Plug works. Tested it on a buddy's mower and car ignition. Put it back in, no spark. (See one other post for details)

[Tim Zimmerman]

Plug works, but no spark.

The magneto normally creates a large potential difference capable of creating a spark to "fire" the combustion of gasoline. Apparently, the step-up transformer which produces enough potential isn't causing the electrons to jump the gap on the spark plug.

I adjusts a coil near the edge of the flywheel and found only two sparks (via high-tension wire and ground) during a start attempt. A second start attempt results with no sparks. A third attempt results with two sparks after a minor adjustment to the coil.

The flywheel where magnet is embedded is left alone, maybe this could be the problem.

So as the flywheel goes around, the magnet passes by the coil. And should create a rapidly changing magnetic field which induces a current in the coil, but this isn't happening. Is a magneto ignition system good only for airplanes? What are some possibilities I can do to achieve a consistent spark?

[Goedjn]

When my car acts like that, it's because the cable(s) that go from the distributor (or whatever they call the electronic version) to the plugs are shorting out somewhere in the damp. In that situation a couple hours with a hair-dryer, and/or a can of chemical wire-dryer usually fixes it long enough to get the car home.

Are you sure you dried everything out throuroughly? dampness in the wiring harness can be depressingly persistant.

[Stormin Mormon]

Airgap from flywheel to the coil should be about .014 or so, which works out about the thickness of a cardboard box from spark plugs.

Coil should be dry to work.

Grounding wires to shutoff switch should be insulated, and not grounded.

We talking points or electronic?

[MUADIB®]

I think we all wonder the same thing here. with points, if it's a Briggs, some models ( most thatI have dealt with) have opints with the condensor built onto part of it. I would replace the points/condensor as a precautionary anyway ,............if it has points. They might be salvageable, but at the price, I'd just replace them.

Remove "YOURPANTIES" to reply

MUADIB®

one small step for man,..... One giant leap for attorneys.

[Tim Zimmerman]

"Goedjn" wrote in

Yes it's dried. It was operational before it was rained on. I have one other mower which was also rained on. This one had been dried for months and still no-spark.

The latest one had been dried for only two weeks.

[Tim Zimmerman]

"Stormin Mormon" wrote

Possibly points. The points could be under the flywheel, and to remove the flywheel, I need special tools. I'm thinking of installing an electronic ignition conversion kit, which might cost less than the tools.

Before converting, I will do more checkup from the new advices.