24hp Briggs Intek won't start

[Scrubcadet10]

Try spraying some down the plug hole, and reinstall the plug, if it fires it's probably a valve/timing or spark issue. (Let a expert confirm that)

 

[Go-Rebels]

No, won't fire at all.

If it won't fire normally, backfire through the carb or backfire through the muffler, then I doubt you have a good spark. Bad timing won't stop ignition; bad timing only fires the fuel mixture at the wrong time.

 

[Tinkerer200]

If it won't fire normally, backfire through the carb or backfire through the muffler, then I doubt you have a good spark. Bad timing won't stop ignition; bad timing only fires the fuel mixture at the wrong time.

Yeah, doesn't add up, has spark, won't fire on starting fluid, flywheel key OK. Check under valve cover. Hard to believe something out of place on both, this engine will run on one cylinder.

Walt Conner

 

[Millstone Farm]

Ok, if it's the spark, what will fix that? New coil? Magneto?

 

[Tinkerer200]

Ok, if it's the spark, what will fix that? New coil? Magneto?

On these engines when ignition spark is suspect the first thing to do is disconnect the "Kill wire" from the BASE of each ignition coil then see if engine will start. The Kill Wire Harness contains diodes which sometimes fail causing all kinds of problems. As I said before, these engines will run on one cylinder and not likely both coils will fail at once and these coils are very reliable.

Walt Conner

 

[Go-Rebels]

Can you measure the resistance of each coil?

 

[Go-Rebels]

I filled the tank with gasoline and tried to crank it; nothing. So I figured maybe trash was in the carburetor. Tore into the breather and discovered the filter had been leaking and the carburetor was full of dirt. I removed the carburetor, cleaned it meticulously with carb cleaner, toothbrush, air and rebuilt it with new gaskets, float valve and a new solenoid. Cleaned out the breather housing and the intake manifold, installed new fuel lines, new filter, new fuel pump, new plugs and checked them for spark. The plugs are sparking and the clean carburetor is getting fresh gas but she still won't start.

How do you know this?

 

[Tinkerer200]

Can you measure the resistance of each coil?

As I said before, these coils are very reliable and both are not going to fail at once and it will start and run quite happily on one cylinder.

Walt Conner

 

[bertsmobile1]

Each coil fires every revolution so it is difficult to understand that you are not getting at least a pop or backfire with some starting fluid directly down the plug hole.
So some fundamential questions
1) are the pistons going up & down in the bore
2) are the rockers going up & down as you turn the engine over.
The only thing I can think of is the key has sheared and the flywheel is spinning on the crankshaft or the camshaft has sheared and the valves are not moving.

As Walt has already mentioned , these engines run happily on one cylinder & I regularly have people complain that they thought the mower was underpowered from new to find it has only been running on one cylinder from new.

 

[Millstone Farm]

Pulled the valve covers and found it. One pushrod on the right head is severely bent and one pushrod on the left head was detached. So I ordered a whole new set of pushrods and gaskets. But what could cause a pushrod to fail on both cylinders at the same time?