Engine starts, runs for awhile, then stops

[GaryGnu]

I have mower that has a B&S engine Model 120000, series 625, 650 or 675, not sure from the manual. Bought in 2009. I regrettably do not have it serviced regularly.

I was having all kinds of problems with it last season. Would not start. Gave up in the fall. Gas evaporated over the winter.

Today I put some gas in it and it started right up! I ran it for awhile and in conked out. I never really got it going strong again. It's running at low power. If I try to turn on the blade, it just stops. It's not really running rough. It's just not full strength.

Figuring this is non-essential in the pandemic, I need to fix it myself. Any ideas? Fuel filter? I've never worked on a small engine, or large engine for that matter. But I am somewhat mechanically inclined.

Thanks for any help.

Gary

 

[mechanic mark]

Post engine model # xxxxxx, type xxxx-xx, code xxxxxxxx numbers. Read your Operators Manual thoroughly & also your B&S Engine Manual. You will need to adjust valves with engine cold, specs. will be in Engine Manual. Purchase Tune-up kit for your B&S Engine. New air filter, spark plugs, fuel filter, oil, oil filter if applicable & B&S Fuel Treatment for your gas can will be included. You will possibly have to purchase a new mower blade if it is cracked, warped, chipped up or pieces missing. Belts, idler pulleys need to be inspected. Grease & lubricate mower per instructions in manual. What name brand mower & model number do you have?: You will definitely need tools, safety glasses, & mechanics gloves. Let us know how it goes, thanks, Mark

 

[dougand3]

The engine model # is probably on the shroud above the muffler.

 

[GaryGnu]

126T02-0256-B1 09042456

I have replaced air filter and spark plug recently.

Toro 20333

 

[dougand3]

Suspect carb is dirty and varnished. You can get an overhaul kit, then clean and rebuild carb. Should be Briggs 498260. You may get by just with removing bowl (careful with gasket or you'll need one) and rod out jet with phone wire. Check youtube for videos.
A simpler solution (esp if new at engine repair) is get a new carb. OEM = $55. AfterMarket = $10. Is this an AUTOCHOKE engine? That carb is Briggs 799866. Primer bulb version is 799868.

 

[GaryGnu]

It is AUTOCHOKE. I got some carb cleaner yesterday. I've seen that phone wire thing on videos. Going to give that a try now. Thanks.

 

[GaryGnu]

The carb cleaner worked. I sprayed it inside and all over. I was able to cut my lawn, finally.