Basic push mower maintenance.

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Jul 26, 2004
New Bri-en, CT
First of all, I have an electric mower so I don't have to deal with stuff like this, but the woman who cuts my hair with whom I have become friends asked me to look @ her push mower because it was chugging after warm up.

It is a Poulan Pro w/ B+S 550 series mower, about 3 years old. I changed the oil at the beginning of the season; this was the first OC since purchased. Definitely < 50 hours on it.

I pulled the plug and it was very sooty as was the muffler. Looked at the oil and it was jet black. Started it up and a giant cloud of oil smoke came out...

Started taking stuff apart and the AF was completely clogged. This probably explains the whole thing. Rich mixture=sooty exhaust, fouled plug, chugging and most likely diluted oil (leaking down the valve stem)

I water washed the AF, cleaned up the S.P. and told her not to use it until the oil was changed. The chugging is completely eliminated.

Long winded to ask
1) Can I water wash the foam filter? Is is a dry or oiled.
2) Do I need to gap the replacement plug i purchased?
3) What other stuff should I do to get this back to top condition? She can't find the OM.

Her 25+ yo son is getting tutored on these maintenance items, although I don't mind helping her out. I kinda sweet on her 8)

edit: just found this
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The old foam air filters can be washed in warm water and mild soap. Dry COMPLETELY. I used to squirt a little bit of light oil on them and then wring out so that there was only a light oil coating left, but I dont' know if its really necessary.

Gapping a plug is always a good idea- shipping and handling can close the gap somewhat.

IIRC, that model engine uses the old above-the-fuel tank carb (Pulsa-Jet), and its a high-failure component. If it still doesn't run well, you might need to "kit" the carb. Trouble getting those carbs to work right is the big reason I prefer the bigger B&S flathead with a gravity-feed float type carb, but then those really want a shut-off valve in the fuel line to protect the carb during storage too.
See how much new parts cost. If a new filter is like $7 and a new plug is $5 just get that instead of cleaning.

Change oil, check fuel is fresh and good and dribble in some fuel injector cleaner like redline si1 which also claims to stabilize.
Alsi change a new blade, or sharpen. Just like a sharp knife in the kitchen this will make a big difference in the actual cutting
Clean the air filter, do not oil it. Change the plug. Change the oil. Put in gas and go cut the grass. It will run a long time.
Will do. Turns out a B+S service place is near by; I think I'll just get a new filter and plug, change the oil, and put a few squirts of FP-60 into her gas can. I'll also do a visual on the blade. Thanks for the help.

I save those black plastic frozen dinner trays for soaking the air filter in oil.

You wanna get it completely drenched in oil before ringing it out.
Yes, as merkava says, always soak the filter in oil after cleaning, which can be done with soap and water, but needs to be dry before oiling. After soaking the filter, squeeze out everything you can, wrap in a rag and squeeze some more. You won't get out to much, as you only need to leave a film in the pores of the foam. DO NOT use with a dry filter, even with a new one, unless it is a pre-oiled one. I have seen times when someone cleaned a filter, then only squirted a few drops of oil on it, then mowed in dusty conditions, and the dirt went right through every spot that didn't have oil on it. A foam filter is great if oiled, but will only catch large chunks of rocks and low flying birds if dry.
Originally Posted By: toneydoc
Clean the air filter, do not oil it.

Incorrect. Briggs and Stratton recommends that foam oil filters be oiled.

This is directly from their website:

Saturate the element with engine oil. Then, squeeze it to spread the oil throughout. Please Note-too much oil will "choke" the carburetor and cause black smoke to emit from the exhaust muffler.

FYI, I don't bother cleaning them, unless they are barely used and like new. The filters are only about $4, the correct Champion spark plug is $2 at Wal-Mart, and 20 ounces of SAE30 or synthetic 5W30 oil will set you back $2.
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