Toro (B&S engine) Push Mower Won't Restart When Hot

[benjamming]

Toro push mower model 20055 with Briggs & Stratton engine model 126T0-0206-B1
Bought in July 2007 so 13 years old with ~150 hours on mower. For a couple years now, the mower won't restart when hot if I have to stop & refill with gas, i.e., it's shut off for more than 5 minutes). I have to let it cool off for an hour or so. It will usually restart if it simply gets bogged down, so shut off for less than 10 seconds or so.

New Champion plug has already been installed. New B&S air filter has been fitted. Still no dice. Oil was also changed this year & level is good.

Thoughts on issue?

Thanks.

 

[spasm3]

Check for spark when it won't start.

 

[benjamming]

What's the coil resistance supposed to be when cold vs. hot?

 

[stangguy]

In my experience of being a Briggs dealer for nearly 50 years, it is most likely the electronic ignition /coil that acts up when hot. It may even still have spark, but it seems not enough, and very hard to test. Best test I have found is to replace it with another one. Not that hard to do, only takes a few minutes. Probably can get one on line for not too much.
Just something I noticed, if you only have 150 hours on it, after 13 years, do you use it very little every year, or did it sit unused for a long time?

 

[benjamming]

Yeah, I used a riding mower from 2014-2018. It takes about 1hr 15 minutes to mow the yard if not too big.

 

[Snagglefoot]

I’ll vote coil but test the spark plug to see. I like the spark plug gizmos you can by for $7.50 or just pull it and ground it. Every auto parts store sells these and everyone should own one IMHO.

 

[Kestas]

I once had this exact problem. I traced it to a keyway that partially sheared, throwing the timing off enough to preclude a hot start.

 

[qjohn]

I had a similar problem on the same type of Briggs engine and the problem went away after I replaced the the coil. It had a weaker spark when hot.

 

[dvancleve]

Howdy folks, tagging in here with a similar issue but on a MUCH older Toro with a Tecumseh engine. For the past couple weeks, when I shut the mower off to move from the front yard to the backyard, I haven’t been able to get it to restart. The first time, it eventually restarted after sitting for a while. The following week I couldn’t get it restarted at all. Today my genius plan was to start in the back (since it didn’t get mowed last week) and not shut the mower off. Alas, it just petered out shortly after I started in the front. I heard the idle dropping, so I tried to keep it running by playing with the throttle but it died and wouldn’t restart. It has gas, the plug is relatively new, and it generally starts in 1 or 2 pulls. Any ideas?

Thanks, Doug

 

[slybunda]

Hot start or running issues like the last thread on here turned out to be spark plug. Plug looked good but when changed out issue was resolved

 

[boom10ful]

The Tecumseh engines have soft keyways. I'd take off the flywheel and check it to make sure it's not partially sheared.

 

[andyd]

The Tecumseh engines have soft keyways. I'd take off the flywheel and check it to make sure it's not partially sheared.
Hmmmn Maybe that could be whats up with the Tecumseh I've messing with . Definitely gonna check it out. Thank You

 

[ripcord]

Is this an auto-choke model? If yes, next time it won't start when it's hot, take off the air cleaner and look down the throat of the carb to see if the choke is closed.

 

[dvancleve]

Is this an auto-choke model? If yes, next time it won't start when it's hot, take off the air cleaner and look down the throat of the carb to see if the choke is closed.

I’m no mechanical genius, not sure if it’s auto choke. It has a bulb you give a couple pushes before you pull it when it’s been sitting for a while, otherwise it just has a throttle…

 

[cvlw]

My current push mower had these same symptoms. After poking and prodding I found shutoff lever cable had stretched. Tightening it up about 1/4 inch seemed to resolve it. I guess it was just enough when cold so that it started but hot was no dice.