Riddle for you

[jonvh]

I've got a riddle for you:
"What has an engine that attempts to start, has a spark at the plugs, clean carburetor and air filter, gas in the tank, yet will not start up?"

Answer:
My lawnmower!

Ignition coil is good and I'm getting a spark. Fuel filter is clean and fuel is getting to the carburetor. I haven't pulled it apart to confirm, but when I spin the flywheel by hand, I can hear the valves opening and closing. I'm not sure that brand matters, but it's a Briggs & Stratton. Battery has good charge. Any idea of where I should start looking?

Thanks in advance, please let me know if additional information is needed.
-Jonathan

 

[bertsmobile1]

Cute
Brand and model numbers DO MATTER as does the type of MOWER.
Your problems fit a broken fuel solenoid perfectly but if it is a push mower then you won't have one.

SO very general
Tip a small amout of fuel down the plug hole & try to start.
Engine fires = ignition timing is good
Do the same at the carburettor & engine fires then valve timing is good and you have a fuel supply problem or choke problem.

 

[Tinkerer200]

Battery has good charge? Then maybe ridding mower? IF so,check the flywheel key and next time when asking an engine question, post the engine make and model number, makes a difference.

Walt Conner

 

[Rivets]

If you can hear the valves opening and closing, you’ve got great hearing, plus something is not right in the valve train. You should not be able to hear valve movement.

 

[jonvh]

Cute
Brand and model numbers DO MATTER as does the type of MOWER.
Your problems fit a broken fuel solenoid perfectly but if it is a push mower then you won't have one.

SO very general
Tip a small amout of fuel down the plug hole & try to start.
Engine fires = ignition timing is good
Do the same at the carburettor & engine fires then valve timing is good and you have a fuel supply problem or choke problem.

This is on a Briggs & Stratton 42E707, circa 1994. I don't see a fuel solenoid valve. Do they all have them? Also, got a backfire when I put some fuel down the carburetor, then nothing.

 

[Rivets]

With that engine,type and code numbers will be helpful.

 

[tom3]

Do you know the history of that motor? Did it run last fall? When you rotate the engine by hand can you feel compression on both cylinders?

 

[bertsmobile1]

This is on a Briggs & Stratton 42E707, circa 1994. I don't see a fuel solenoid valve. Do they all have them? Also, got a backfire when I put some fuel down the carburetor, then nothing.

So what happens with fuel down the plug hole ?
Backfire, through the carb or through the exhaust .
IT makes a difference and as per Rivets post the full number is really needed.
And have you checke tosee if the timing key in the flywhel is still in the right position ?
No need to pull the flywheel, just undi the fastener and check that both halves of the key slots make a perfect square .

 

[biggertv]

I've got a riddle for you:
"What has an engine that attempts to start, has a spark at the plugs, clean carburetor and air filter, gas in the tank, yet will not start up?"

Answer:
My lawnmower!

Ignition coil is good and I'm getting a spark. Fuel filter is clean and fuel is getting to the carburetor. I haven't pulled it apart to confirm, but when I spin the flywheel by hand, I can hear the valves opening and closing. I'm not sure that brand matters, but it's a Briggs & Stratton. Battery has good charge. Any idea of where I should start looking?

Thanks in advance, please let me know if additional information is needed.
-Jonathan

Sheared Key. If it's too buggered up to fix, put flywheel in correct position, drill through fly and crank install roll pin or similar.

 

[jonvh]

So what happens with fuel down the plug hole ?
Backfire, through the carb or through the exhaust .
IT makes a difference and as per Rivets post the full number is really needed.
And have you checke tosee if the timing key in the flywhel is still in the right position ?
No need to pull the flywheel, just undi the fastener and check that both halves of the key slots make a perfect square .

Sorry, it's been a couple of days since I've been able to look at it again. When I put gas down the plug hole it backfires. Full number is 42E707-2631-E1. Would the flywheel key be sheared from top to bottom? I can view it from the top if I remove the large nut. It is square. But, obviously, I can't see the bottom of the key.