Hello All,
New here. Trying to resolve an issue with a used Snapper that I just purchased. Machine was working fine and then all of a sudden the engine quit. Briefly: good spark, good fuel and flow to carb, clean air filter. Dont think I have an engine issue, rather some kind of interlock/switch issue associated with the mower that is causing the engine not to start. I can try to restart the machine and it will fire 2-3 times and then quit. Temp does not appear to be a suspect here.
I removed the small resin encapsulated PCB that is in a plastic shell under the seat and adjacent to the battery as possible suspect. Not sure what this component does but maybe it is the faulty link. Is there a way to test this component? Ideally, I would like to remove all the safety interlocks from the machine as I feel this will eliminate potential issues going forward. Not sure if anyone has done that but seems reasonable. I am grateful for any thoughts here. The machine is at my girlfriends house an hour away from me. I will try whatever may be suggested next time I go down. All wiring is intact. Machine is in very nice condition and was only lightly used. Machine uses a Briggs Intek 12.5HP motor should that be of consequence. Serial # of the machine is 2014432820. If I have left out any critical info, please just ask and I will add it as necessary. Is there anyway of telling the age of the machine by the serial or model? Thank you very much. Trying to be the hero instead of the zero!!
George
#2
Scrubcadet10
Does the engine have a low oil shutdown safety feature?
Usually the safety switches like the seat switch, are in the cranking circuit and won't let the starter turn the engine.
I am not sure but the starter will work and the engine will turn over about twice before it stops. Oil level is good by the way. Again feel strongly that there is some type of safety switch failing that causes the engine to not want to stay running. Thank you
Take the spark plug out and try to crank the engine
If it spins OK then your decompressor is not working
Next step is to check & set the valve lash correctly
If it still turns 2 revolutions and stops then the cam needs replacing.
Hello
Maybe I misspoke. I should have said the engine will, after it stops running, and you attempt to restart, sometimes will not restart at all and other times I will get two fires out of her. Just seems like there is something going on with the interrupt circuit. Is there a way to bypass that completely just to check? Also, the small piece that I refer to in my original post that looks like a small pcb that plugs in under the seat. What is this component? Thank you for all the great help!!
By the way, after this happened, I wheeled the machine into the garage and kept trying to understand what was happening. I swear that I got it restarted by jiggling around the shift lever. Maybe there is an interlock on there that might be failing. Anyway, ran again for about twenty minutes and once again turned off. Again, if there is a way to bypass all the “safety stuff” I am willing to bet it will start and have no issues but that is just a guess
#7
Scrubcadet10
There should be a black kill wire hooked to the ignition coil, unplug it and try to start,
If it fires up, runs good, shut it off, restart, runs good again then. Maybe then you could isolate the problem to either electrical or mechanical.
Ok. I am grateful. Thank you for the help. Sorry for the newb question but how do I get to that black wire on the coil. Remove the top engine cover with the recoil mech? Thank you
#9
Scrubcadet10
Yes, the coil should be right underneath it, with a skinny black wire running to it. besides the spark plug wire
Excellent. Will give this a try and keep my fingers crossed. I am assum,ing, correct me if I am wrong, that this skinny black wire is what the mowers interlock uses to prevent the mower from starting if one of the switches is awry. Correct? Thank you again.
Should have only one wire like Scrubcadet10 said. The stacked plate device in the left side of the picture is the magneto. That black wire is what you need to trace down. If your GROUND that wire to the mower body, the engine will NOT start or run. That is the ignition kill wire.
The stop switch location can be ignored on a riding mower. The below pic looks to be from a push mower engine.
Thank you for all the kind and informative responses. My neighbor was very helpful in aiding me withy this endeavor as well. Turns out the interlock system was just fine. The culprit turned out to be a very dirty carb. The bottom of the bowkl had lots of shellac in it from undoubedty sitting for a long period without being used. He is in the process of rebuilding the carb and I am hopeful that this will solve the issue once and for all. Thank you all again.
