Briggs suddenly quit - wont start again

[tkappeler]

New member here with a problem with our Toro ready start mower. It is about 4 years old and has worked without problems until this weekend. It suddenly stopped and will not restart. The engine is model 126T05-0115-B1. The plug has been replaced. Gap is .030 per manual. spark looked really weak so replaced the armature. I used a business card to provide the gap as others have done. Pulled the blower housing off and removed a dead mouse from under the carb area.

Fuel is new. Still will not start. I am not sure that the problem is fuel related as it will not so much as sputter with starting spray. I could understand it could be fuel related if it started and quickly died with the spray. If I could at least get a quick start, I will gladly overhaul the carb.

Any help is greatly appreciated.

Tom

 

[tkappeler]

I have also checked that the key is in place, not broken. When I pull the new plug, it is dry. Tried spraying starting spray directly into the cylinder/install plug/turn key on electric starter. Turns over but not a hint of starting.

The new armature has a two wire to one connector kill wire. I assume this is for those engine models that have a separate on/off switch also, one to the kill handle and one to the actual on/off switch if equipped?

 

[Rivets]

Here is what I would do. First, remove the shroud and plug again and check for spark. Do this by spinning the flywheel by hand while holding the plug against the block. Then disconnect the kill wire from the magneto and repeat the test. If the spark is better with the kill wire off, you have a short in the kill wire, which you are going to have to find. If you have good spark both ways, the next thing I would check is the flywheel key. Post what you find.

 

[tkappeler]

Here is what I would do. First, remove the shroud and plug again and check for spark. Do this by spinning the flywheel by hand while holding the plug against the block. Then disconnect the kill wire from the magneto and repeat the test. If the spark is better with the kill wire off, you have a short in the kill wire, which you are going to have to find. If you have good spark both ways, the next thing I would check is the flywheel key. Post what you find.

I did not try the kill wire on/off but will check that tonight when I get home. I was not able to pull the flywheel but could see that the flywheel aligns properly with the keyway on the crankshaft and that the key is in place.

I have not replaced the original kill wire with the new one provided with the new armature but will also try that tonight.

Thanks!!

Tom

 

[nograsstomow]

Here is what I would do. First, remove the shroud and plug again and check for spark. Do this by spinning the flywheel by hand while holding the plug against the block. Then disconnect the kill wire from the magneto and repeat the test. If the spark is better with the kill wire off, you have a short in the kill wire, which you are going to have to find. If you have good spark both ways, the next thing I would check is the flywheel key. Post what you find.

Don't mean to step on original post but have a question for Rivets. What if there is no spark from the magneto with or without the kill wire? Is the magneto at fault?

 

[Rivets]

If no spark with or without the kill wire attached? To me that means time to replace the coil, be cause it is either open or shorted tonground.

 

[tkappeler]

OP here. We have spark, new armature, new gas, pulled carb and inspected, appears ok. No blockages in airway. Flywheel is ok. Key in place. New kill wire. Won't even attempt to fire even with starting fluid and electric start. Any other safety triggers that can come into play? Head gasket? Do not have a compression tester but can get one soon if needed.

anyone?

 

[Rivets]

Only thing left is compression. Pull the plug and insert a long screwdriver into the spark plug hole. Slowly turn the flywheel and see if the piston is moving up and down. If it is, spray a little carb cleaner into the cylinder and see if it will fire. If it does we have a valve problem.

 

[TobyU]

See if it wil blow your finger or thumb off of the spark plug hole when you turn it over.
You can use a flashlight to see the valve move through the plug hole.
You might have a valve not seating all the way...(usually slipped guide) of a valve stuck open and not moving at all.