bad idle when hot - Lawn Mower Forums : Lawnmower Reviews, Repair, Pricing and Discussion Forum

swimm397 · 04-27-2012, 04:25 PM

Picked up a walk behind lawnmower from my mom, said she was having problems with it idling funny. Maintenance had never been done to it, so i replaced the spark plug, air filter and gave it some fresh oil and gas hoping that it would solve the problem, and of course it didn't. I have not replaced the blade, even though it is beat to **** and needs to be replaced.

So here is the deal. When i first start and run the mower, it runs great, good idle and everything. But after running it for a while the idle starts to go up and down.

Anyone know what could be causing this issue and how to fix it?

twocycle · 04-27-2012, 05:17 PM

To The Forum!! What is the model name and model # of the Toro mower you are working on? What type of engine is on the mower?

swimm397 · 05-02-2012, 12:48 AM

Ya i guess that would be important information huh haha. Sorry for the delay, finals week

It's a 6.0HP GTS 21" Personal Pace Recycler, model # 20022. Bought back in 1999.

swimm397 · 05-02-2012, 01:00 AM

engine is a Briggs and Stratton Model # 12H802-1767-E1

**Mark / Ohio** · 05-03-2012, 12:25 AM

Try loosening the fuel cap when it is acting up and see if it smooths back out. Vent might be partly plugged.

swimm397 · 05-03-2012, 02:58 PM

how would i go about clearing the vent if it is clogged?

Austen · 05-03-2012, 09:21 PM

Quote:

Originally Posted by swimm397

how would i go about clearing the vent if it is clogged?

Find something small and sharp that you can use to stick through the hole such as sewing needle/toothpick etc.

Depending on the application, you may need to also remove the gasket on the bottom of the cap for better access vs. doing it through the top.

swimm397 · 05-03-2012, 10:02 PM

Ok, should i just go through the whole exhaust system and make sure its no clogged up?

**Mark / Ohio** · 05-04-2012, 12:42 AM

Being a 4-cycle engine it is pretty unlikely that there is an exhaust blockage. My bet is a lean fuel mixture. Could be carburetor but since it runs ok until warm was my reasoning for thinking maybe fuel tank drawing a vacuum from a plugged vent.

swimm397 · 05-09-2012, 12:54 PM

What other possible vents may there be. I took a look at the gas cap and i did not see an sort of vent hole.