Surging mower

[Jim]

Craftsman 143.396022

Last year before putting the mower away for the winter the engine would surge. Often if I babied it I could get it to run fast and I'd just do with it.

I'd like to rectify this before the true mowing season gets here. Couple questions:

Is the fuel bowl held by threads? I don't see any nut or bolt to loosen.

How do you adjust the governor? I only get limited reaction to the idle mixture screws. But a tap on the governor bracket brings instant response. At this point I've play with the two screws but can't say I've made any effective difference. I've tried spraying the linkages with carb cleaner to remove any gunk.

[William W. Plummer]

Is it a Briggs and Stratton? What you describe is usually cured by doing a carb rebuild. You can get a kit at small engine stores. Usually the only thing that matters is the diaphragm in the middle of the carb so don't bother with all the jets, etc. Or, you can pay for a "tune up".

[m Ransley]

Could be the float or govenor linkage,spring or the controling air vane if it has one is sticking.

[Bennett Price]

And make sure there is no water in the gas tank

[Jim]

Believe it is the B&S. I'm reasonably handy with tools but don't enjoy kits with tiny springs, clips, etc. What is the rebuild kit like?

[xrongor]

if you cant figure out how to get the fuel bowl off, i think its safe to say the rebuild kit is over your head.

randy

[ricardo]

B&S Manuals & Illustrated Parts Lists :

Notes on the Troubleshooting and Repair of small Gasoline Engines and Rotary Lawn Mowers: to: Troubleshooting guide >Instant troubleshooting chart - most common problems and possible causes > Problem: Engine operates erratically, surges, and runs unevenly

The above page was linked to from the Sci.Electronics.Repair (S.E.R) FAQ:

of other good info ;but, unrelated to your problem.

[Jim]

Researching Sears source codes reveals the engine is a Tecumseh

[William W. Plummer]

You're not going to want to hear this -- I have a Sears lawn tractor with a Tecumseh motor. It has run for 17 years with no carb problems. Note that I have never attempted to "adjust" it for any reason.

[Stormin Mormon]

Last year before putting the mower away for the winter the engine would surge. Often if I babied it I could get it to run fast and I'd just do with it.

I'd like to rectify this before the true mowing season gets here. Couple questions:

Is the fuel bowl held by threads? I don't see any nut or bolt to loosen. CY: yes, it's t here, look for it. I think 7/16 open end wrench.

How do you adjust the governor? I only get limited reaction to the idle mixture screws. CY: You replace both of these springs:

SPRING, EXTENSION 34043 7

SPRING, CONTROL 35203 11

But a tap on the governor bracket brings instant response. At this point I've play with the two screws but can't say I've made any effective difference. I've tried spraying the linkages with carb cleaner to remove any gunk. CY: OK, good start. But if the speed is undependable, clean out the carb, and replace the two springs that atach to that arm that sticks out of the side of the engine.

[Jim]

Did you see my note about it actually being a Tecumseh? I ask because of the reference to the springs.

Looks like my project for the next dry semi-warm day will be to pull and clean the carb. Considering to very cool weather still around here that might be awhile.