I have a Briggs and Stratton 12hp engine in my ride on mower that will not start. I have replaced the battery and starter, and have cleaned the carburetor. The engine turns over slowly as if the battery is low on charge (although I have charged it up) and there is a good spark at the plug. I have tried jump leads off the car, but it does not help. Any ideas?
By gd21 from Sunshine Coast, Qld
Here are the recent answer to this question.
Also it might not be earthing properly when you replaced the starter motor and battery.
Go to youtube type in cant start whatever model mower wont start and lots of videos will show you how to. All kinds of mowers. No harm in trying.
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My mower with a B&S (Briggs & Stratton) engine won't start. Per feedback from others concerning similar problems, I took plug out still attached to wire, there was no spark when I pulled cord. The plug snapped in so it had a good connection. The first time I pulled, my wife said it shocked her, but no spark. (Holding it in the wrong place?) After that, nothing. It was daylight and in the shade, would we see a spark? Also, a couple of weeks ago it started fine with the old gas still in it. Then I changed the plug, filter, oil and blade. I didn't change the gas, but I did add new gas. I also rinsed it off with a hose pretty thoroughly. Any of this give anyone any ideas? I'd appreciate any tips. Terry from Charleston, SC
By Tom Mann.
By Sherry Nelson
It may have water condensation in the gas tank / line. If it has water in the gas line or tank, you can take it to a repair shop and they will do it in within 30 minutes time for typically 50-80 bucks, or do it yourself. I was told water in tank or gas line was not a covered warranty issue.
I read on another site (do at your own risk):
1. remove the gas line from the gas tank and have container to catch the gas coming out. You may need two containers. One to catch the gas thats coming out and another, larger container to dump the gas into.
2. Once tank and line is empty, locate the carburetor bell housing. On a Briggs and Stratton engine, it looks like a silver bell. There is a 1/2" size nut at the bottom. LOOSEN, but dont take apart, and let the gas leak out, mine only leaked out 3-4 tablespoons of liquid. Once it stops dripping ( 3 minutes or less) , tighten bolt and put all gas lines back on.
3. Clean up excess gas spillings, and add more known good gas in tank, and about 1/4 or less of dry gas or carb cleaner. Apparently Lowes sells a product that helps remove water out of gas mower tanks better than Isopropyl Alcohol.
4. If accessible, I removed the air filter and had a folded napkin ready to help block that hole . I had my son try starting the engine, and it started, and I used the napkin to block air flow. It helped suck out all air and water out of the mower. Just before it was ready to stall, I took napkin off hole. If mower stalls, start it again, use napkin as necessary, repeat again until it it runs normally. Only had to use napkin twice.
Make sure your gas is good, it can be cheap unleaded, and it should work fine. if it doesn't it either has a Boatload of water in the machine, or thats not the probem.
Hopefully this helps and makes sense. (11/07/2007)
By major tom
I'm working on a 12Hp Briggs which powers a ride on mower. It won't start and a compression test revealed it had only 7psi dry and 10psi wet. I've stripped the engine bare and can't find a single thing wrong with it. The engine has completed perhaps 100 hrs. Everything inside the engine is as it should be. It has electric start, so I would have expected more than this small amount. Has anyone any idea what the compression pressure should be?
David from England, UK
I have a Briggs and Stratton riding lawn mower, Model 42A707. I just replaced the battery. When I turn the key, you can hear the starter spinning...
I have a 14hp Briggs engine on my lawn tractor. It will not start, it has no spark, and has plenty of gas. I have checked all of the safety switches. I have actually jumped them out and still no spark. Where else can I look?
By skynyrd57 from PA
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