Posted: 7/18/2012 7:57:31 AM EDT
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Lawn mower with a briggs motor circa '05, from lowes. The motor runs great, when it runs. Starts on the first pull. It has the auto throttle & choke. I have checked the fuel supply, fuel, carb, oil, and everything else I can to narrow down the problem. It has developed an issue seemingly electrical.
It will shut down at random, sometime not to restart for a period of 30 minutes to a few days. I have sent the wife to get a new plug as I type this. What and how can I check the electrical parts? What parts could go bad and what would their symptoms be like? Thanks, SS ETA changed the subject to engine and not motor. |
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http://www.briggsandstratton.com/support/frequently-asked-questions/
Remove the spark plug and check for spark when starting. Could be faulty kill switch or capacitor. |
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When I check a small motor I
1. Pull plug and check for spark. I just usually touch it to the bare block. Should get bright blue spark. red-orange spark is generally going to mean a problem in the coil / points / condenser or magneto. (also check the spark plug for cracks, and that its gapped correctly) ––no or weak spark I continue down the list. ––has good spark I move to checking fuel 2. Check boot and wire continuity 3. Check Safety features and kill switch. Check the whole wire run, test for grounds. Should be open in run position and grounded in kill/stop position. 4. Check points / magneto 5. Check coil (especially the ground) Fuel loosen fuel cap. Prime the engine, full choke and try to start. (Leaving spark plug out). While trying to start look into cylinder, should see gas spray into cylinder. If I dont see it then I tighten down carb mounts to squeeze the gasket. If the gasket is leaking then you may not be able to suck gas from the tank into the cylinder and instead you suck air in through the leaky gasket. Try again. Still no gas then I pull apart the carb, double check gasket for cracks, clean or rebuild depending on what I find. Got Gas but still won't start then I check compression. Put thumb over spark plug hole and crank. Should move your thumb off. If you have a gauge handy then you should get more than 50 psi On a 2 stroke its should be higher still, so I look for anything over 60. If you have weak compression then pour a little oil into the cylinder through the spark plug hole and try cranking a few times while checking compression. If compression rises then you have worn rings, no gain indicates a valve problem. Sounds to me like your gas cap isnt venting and you can run a little while then it pulls a vacuum and starves the fuel. OR Your fuel is too rich. Oil is fouling the spark plug causing it to die and preventing you from restarting it. (pull the plug and and check it when it dies next time. Look for black oily deposit/layer. gonna have to stop there. Too tired, just got off work from night shift. Gonna go catch some shut eye. I will finish this post off a bit more if these things do not solve your problem. |