Strange problem starting mower

[Castingman]

Have a Toro 22" Self Pace Mower, Model 20332, S/N 310001541, purchased in 2012. Mowing my yard takes 35-40 minutes and I estimate it's run for about 400 total hours.

Early this year it would start after 3 or 4 pulls. Lately though it takes 15 or so pulls to start. When it does start, the RPMs vary slightly for about 30-40 seconds and then stay constant and it runs great. It never stalls while mowing.

I've put in a new spark plug and air filter but the problem persists. (The old spark plug is only 2 years old and looks OK. The air filter was new last fall.) I use gas that has 10% ethanol and I add stabilizer. I put some of my gas in a clear container and let it sit for about a month and it shows no sign of water.

I have discovered a weird work-around. I tip the mower 90 degrees with the gas tank up. Wait a minute then put it down and immediately try to start it, and it does with 1 or 2 pulls. If I wait a few minutes after putting it down on its wheels, it takes many pulls.

I'd take it to the Toro repair shop but that's 50 miles away and I'm high risk for Covid 19 so that's not an option.

Hope you experts can point me toward a solution!

 

[ILENGINE]

You don't say what engine you have so can't give specific info but it sounds like it could use a carb cleaning. Partially clogged jets are not passing enough fuel for cold start.

 

[tom3]

Is this a Briggs engine? Might have the automatic choke with an air vane that pulls it off. Could be some binding in the linkage that is preventing the choke closing?

 

[Scrubcadet10]

i typed in your model on toro and Serial number and it says you should have a Briggs 128T02-3125-B1
The parts diagrams do not show this mower using a Primer bulb, instead it has an autochoke. If it does in fact have an autochoke:
First, when the engine is stone cold, remove the air filter cover and filter, you should see the choke valve right behind the filter base, and it should be closed. I'm wondering if you tilting the mower allows some fuel up through the main jet making it easier to start.

Parts – 22in Recycler Lawn Mower | Toro

www.toro.com

 

[tom3]

I know all about the autochoke but I still had to watch Tarryl's video just for fun.

 

[Castingman]

There is no primer bulb so a stuck autochoke seems likely. Busy today so I'll dig into it tomorrow and let you know how it goes.

I always wondered how it worked with no primer bulb or manual choke. Nice to learn something new. Many thanks to all who replied.

 

[deminin]

I have a similar Toro mower...also 10+ years old. Last year, after sitting all Winter, it became very hard to start...10+ pulls. I didn't see any issue with the choke, and the filter and plug were good. On a hunch, I filled a gas can with Premium unleaded/no ethanol, added a couple of tablespoons of carb cleaner, and ran the mower for a couple of hours with that mix. After that, it started with 4 or 5 pulls, and after mowing 3 or 4 times with that hi octane mix, it consistently now starts with the 2nd or 3rd pull. I suspect the Ethanol had gummed up the carb after sitting all winter. At the end of the mowing season, I ran the mower until it ran out of fuel, and this Spring it started on the 2nd pull, and did so all year long. I think mowing is done for this year, so this weekend, I will run it out of fuel, so the old gas doesn't clog up the carb, and hopefully it will continue to start/run nicely next Spring.

 

[Castingman]

A couple unrelated things came up so I didn't get to the mower until late today. When I took off the air filter I could see the choke was open. Removed the top cover, tank and second cover. (That video really helped.) The choke had moved to the closed position. (Wasn't watching it so I don't know what made it close.) The thermostat on the muffler is ok. The small spring is ok. Blew out all the clippings and lubed the pivot on the long arm that controls the choke. Everything seems to move easily now.

Reassembled all except for the top plastic cover so I could watch the choke. Mower started on the fourth pull. As soon as the engine started, the long arm moved and opened the choke. (I assume the air off the flywheel blew the arm open.) Let the mower set for about 25 minutes and then started it with 3 pulls. Seems to be fixed now. I'll get some carb cleaner for the gas to clean out any gunk.

Thanks again to all who responded.

 

[Fish]

In response to the turning on it's side tecnique.

Likely some fuel dribbles out of the carb into the intake throat,

and it is just like giving a shot of fuel {prime} to start.