Kubota Z122EBR won't start

[Wiz]

Kubota z122EBR (residential gas) mower. 154 hours. Purchased used with a little over 100 hours a couple of years ago. It has a 22 HP Briggs & Stratton Professional Series engine.

Won't start:

• Cranks fine, just doesn't seem to fire
• Spark testers show spark on both cylinders (one may be weaker than the other. Hard to tell in daylight)
• Spark Plugs changed last season.
• Lift your butt off the seat, won't crank
• If the parking brake is not engaged, it won't crank
• Engage/disengage the mower deck I hear a click, and won't crank while engaged.
• Move either steering bar in, won't crank.
• I see gas in the fuel filter.
• The tank was about 1/4 full when it died. Added more gas.
• The engine has oil. The last time it was used, which was the first time this season, it was running poorly and I parked it. Later when I checked on it, it had an oil puddle under it and discovered the oil filter had come loose over the winter and it was low on oil. I changed the oil and filter. It ran fine for 45 minutes or more before dying.

Looking for where do I start to diagnose? TIA!

 

[North Idaho Wolfman]

Get the WSM (aka service manual) it will have steps on what to check.

I would pull the plug on the fuel bowl and check that for fuel and junk.
Then I would pull the fuel solenoid and test that.

 

[Dave_eng]

I have had luck looking on the Briggs and Stratton web site for info and manuals.
Briggs
You will need to find the Briggs info on your engine.
Dave

 

[lugbolt]

you have spark
it cranks over
you have air
do you have fuel and compression??

on these mowers I usually pull the air filter out, give the intake a small shot of carburetor cleaner, then crank the engine over. If it tries to run, you have compression, probably no fuel (carb or fuel shutoff solenoid issue).

 

[Grandad4]

Quality of fuel? It's common for engines with ordinary ethanol blended gas to have fuel delivery problems unless treated with fuel stabilizer. Non-ethanol gas is a better option for small engines, adding stabilizer can't hurt if the gas will sit for extened periods.

 

[OHYO]

Had the same issue on a professional grade Briggs that I used to replace an old tecumseh with a broken rod. The Briggs Was only 2 years old when it started having issues. I removed the carb and sprayed it good with carb cleaner and cleaned out the fuel bowl. I reassembled and it still wouldn’t start. I held my hand over the carb air inlet and it started, When I removed my hand it would die. Put my hand back and restricted, it started again and ran ruff for a few minutes but never died again. I think the jet was clogged and when I put my had over the inlet it created massive vacuum and sucked whatever was in the jet out.