Simplicity Coronet 12 stalls when hot
Posted August 26, 2010 - 10:24 AM
Brand new here. I found the forum while Googling for a stalling issue on a used Coronet 12 I recently picked up. It has a 12.5HP Briggs & Straton engine which seems to run great and starts almost on the first try every time. However, after running for 10-15 minutes and getting nice & hot, the engine just sputters out and dies. After I bought it, I replaced the spark plug, fuel filter, changed the oil, and checked the air filter (clean).
At first, I thought it might have been the safety switch under the seat not making good contact. It seemed like if I bounced a little on the seat while trying to re-start after a stall, it would fire up. So, I used some good ol' trusty duct tape and a small metal disk to permanently depress the safety switch. :) Unfortunately, that did not resolve the issue either.
So, any ideas? What would cause this thing to run fine until it gets hot and then stall? If I let it sit and cool for a bit, it will fire right back up and mow fine until it gets hot again.
Figured I'd get some ideas here before I haul it into my local Simplicity dealer for service.
Posted August 26, 2010 - 10:44 AM
Posted August 26, 2010 - 11:47 AM
After running for 10-15 minutes and getting nice & hot, the engine just sputters out and dies. After I bought it, I replaced the spark plug, fuel filter, changed the oil, and checked the air filter (clean).
What would cause this thing to run fine until it gets hot and then stall? If I let it sit and cool for a bit, it will fire right back up and mow fine until it gets hot again. Dave
I had the same problem with a TORO built Lawn Boy. Mine would sputter a while then die out. Problem ended up being sticking valves due to shellac. Clean the valve shafts, clean the guides (I carefully hand-ran the right size drillbit down the guides. ) and try it again, couple hours & a couple gaskets. Might just do it. Or, if not comfortable with all that, the dealer is always an option...
If that fixes it, run some 2-cycle mix once in a while to keep it from happening again.
It might also be a bad coil... Anyone else?
Posted August 26, 2010 - 03:17 PM
Is your fuel line next to an extreme heat source? The fuel could be vaporizing in the line....
Posted August 26, 2010 - 10:25 PM
Posted August 27, 2010 - 07:59 AM
Good luck on finding your problem and glad to have you here as a member!
Posted August 27, 2010 - 05:37 PM
Posted August 28, 2010 - 02:01 PM
Posted September 10, 2010 - 08:25 AM
I just wanted to say THANK YOU to everyone for all the great suggestions -- all input is very appreciated! I'm going to check the air vent in the gas cap and check for anything under the heat shroud. Beyond that, I think I'll be taking it into my local dealer for some repair work. I'm not about to tear the engine apart because I'd probably never get it back together. :)