Only starts with starter fluid but runs thereafter

[Zimber]

I have a Toro SmartStow 22" Recycler 190cc with a Briggs & Stratton L-Head. Was running one day and then next weekend it would not start. I cleaned the carb multiple times with ultrasonic and with carb cleaner. All the holes seem to be clear. I put a new gapped plug and fresh fuel. It is one of those guaranteed start engines so there is an automatic choke and no primer. Prior to a week ago it worked perfectly and always started on the first pull. Mow multiple pulls and it won't start. I remove plug an it of course is wet. I blow out plug and cylinder with compressed air and then manually force the choke open. Same thing. Could it be that the float seat got hard suddenly and therefore the needle valve is not seating and therefore flooding? Any insights appreciated. BTW I checked valves and they do not turn at TDC and the lash seems ok. I didn't check compression but the cylinder does not appear scored.

 

[GearHead36]

Sounds like a problem with the auto choke. I have a similar mower with a similar engine. There is an air vane that actuated the choke. There is a spring on that air vane. The spring on mine went missing, and I had the same symptoms you have. Well, almost. I could start it without starting fluid, but it would take 10 pulls. After I replaced that spring, it takes 2-3. Your problem might not be that spring, but it sounds like a choke problem.

 

[StarTech]

Valve seeming to be fine is not the same as being within specs. With L-head the clearance closes up to near zero but yet the valve wouldn't spin when closed but you are losing most of you compression just before TDC.

Also some engine actually need the choke plate changed out at times. Just did a manual choke one here where it would not start with the choke fully closed. IT had the original choke setup but the engine is a 2003 model. After changing the vane out it starts on the first pull now. Just got un-choke it once started. Funny it was in six shops before mine and they try just about everything.

 

[Craftsman Garage]

@GearHead36 X2

 

[slomo]

Pull oil dip stick, smell for fuel.

Is the oil level on the FULL mark? Not over nor under?

Could be a stuck open carb needle.

I would verify spark as a quick free check.

 

[slomo]

I cleaned the carb multiple times with ultrasonic and with carb cleaner. All the holes seem to be clear.

Did you clean the emulsion tube? Any holes plugged up?

I put a new gapped plug and fresh fuel.

Did you check this "new" plug for spark? Does it work?

I blow out plug and cylinder with compressed air and then manually force the choke open

Choke needs to be closed on a cold engine.

Could it be that the float seat got hard suddenly and therefore the needle valve is not seating and therefore flooding?

Possibility. Need to pressure test the carb needle/seat at 7psi for 30+ minutes. Could be sticking closed too.

I checked valves and they do not turn at TDC and the lash seems ok.

There are 2 TDC strokes on a 4 smoke engine. Let's keep it simple. When one valve is fully open, meaning pushed
down into the head, set/check OPPOSITE valve. Rotate the engine. Now the valve you just set needs to be pushed into the engine. Set/check OPPOSITE valve. Intake will have a spec as well as the ex valve. Most are different. Like intake 0.004" and EX say 0.006" for example. Your engine manual will tell you the valve lash spec.