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Push mower advice?

I

iwannadie

NAXJA Forum User
Location
Gilbert, Az
I have a craftmans (briggs and straton) mower. I bought it a good 9 years ago and never had a single issue. Tune up every year and good gas has kept it starting first pull.

Until last week it suddenly took 5-6 pulls to start. It also is suddenly consuming oil. I don't see any obvious leak but there was a bit of grass build up so it could have soaked it up. It also bogs down and wants to stall very easy.

I'm going to clean all the grass off and run it to see if there's obvious oil leak, compression and go from there.

Any recommendations on what to look for based on sudden oil cosumption, hard to start and bogging down all happening suddenly and together?

I know everyone will say buy a new one but if I can fix this for a decent amount of money vs buying a 300$ replacement I would like to try.
 
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Most B&S motors can be rebuilt for about $100. At least that's how much it cost when I was teaching a small engines class five years ago.
 
For the rest of the year, I would pull the plug and put a squirt of ATF in the cylinder and let it sit for a day or two. It will most likely remove the carbon and free the rings. Limp along until fall and you can save probably half on a new mower.

I would put in a fresh spark plug and also clean the foam air filter and spray out the carb with some carb cleaner.
 
Thanks guys. I really would like to limp it along till end of season sales for sure. With my HOA being so strict if I miss a week mowing they flip out. Just sad it went from firing off first pull like normal to all of this with no signs of trouble.

I sprayed the under deck down, no real clogging at all just a few normal stuck clumps. There was a lot lf build up behind the muffler though maybe caused over heating.
 
I messed with it today.

Pulled the muffler off no signs of oil leak or anything out of the ordinary, looks almost new.
Pulled intake it looked fine no signs of oil or being clogged.
Spark plug again fine not wet or a anything weird.
Pulled the little valve cover and the valves look fine. Turning the motor by hand the valve seem to move freely and just fine.

Put a compression gauge on and turned by hand, i have strong resistance but 0 indication on the gauge. Hook up the leak down and gave it just like 10psi, showing 0 again. I can hear air coming from the intake.

With the valve cover off and turning the motor by hand i can see and hear when the air is coming from the exhaust and from the intake like ot should be. When both are closed I still feel air from the intake opening. Also turning the motor, when the exhaust valve shuts and right before the intake opens I get a spot where air escapes from the exahuat when it should be shut. Another tiny bit of a turn and it seals again.

Bad intake(maybe exhaust) valve? Replacement heads aren't too pricey.
 
Give the ATF a try and see what it does.

If you redo the Compression Test and the numbers come up, you have a ring problem. Not saying you don't still have a valve problem, but if you do it and the numbers don't change, think valve.

Every 5 or so years I take the carb on mine and flush the jets and stuff with some carb cleaner. It makes a big difference.
 
Carb or the fuel pickup line are almost always the issue I have when dealing with lawn stuff. I'd replace all the rubber lines. Had a pinhole in the fuel pickup line of my dad's weedeater that would make it erratic and hard start if the fuel level went below that hole.
 
I shot some ATF in after I buttoned it all up. Well see, rings would be easier to deal with maybe. Piston and ring kit is like 40 bucks.
 
Pulled the head off, gasket was intact but the mating surface was wet and oily along the bottom. The block side and gasket were just real wet oily residue. Oil was getting by that much was clear.

Going to try a head gasket and see what that gets me, $6.50 on amazon.

Should note, piston, valves and head were just black with oil. Rings gotta be shot but if a head gasket will help me limp to the end of the season I'll be good.
 
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If it goes the route of replacement motor I'd rather spend a little more and get a briggs and stratton and be done with it. Places have them for like $180.
 
and it's made of chinese components anyway. It's not your daddy's B&S anymore.

predators are solid honda clones.
 
^ this . the higher end briggs stuff is still good but the predator engines for the cash are really hard to beat . Briggs went cheap in the mid 90s junky carbs , plastic cam shafts etc
 
Eh my briggs lasted this long without issue, I'll stick with whats proven with me and not go with a clone.

In general I'm not sure how I feel about companies making knock off clones anyways, thats a bigger subject than my little mower problems though.
 
B&S engines are pretty basic and built with huge clearances compared to other engines.
You didn't state HP, but based on your post I'm going to assume 3.5 to 5.5hp

Oil usage is usually rings, but can also be caused by a clogged crankcase vent filter.
Filter is usually on side of crankcase under a metal plate. Clean and reinstall.
If Valves is pretty basic. Tear it down, put new crosshatch on the cylinder , and replace rings.

Leak down issue, check for carbon buildup on valves and valve seats.

Hard starting, especially after a sudden stoppage can be the flywheel key being partially sheared.

It pays to change oil once a year, clean filters, and avoid walking things with the blade.
 
Mine is a 6.5 hp. I'll check the crankcase vent for sure when putting the new headgasket on.

Cleaned all the build up off the piston and valves, they look new again, no signs of wear on the cylinder walls. The thing looks in amazing shape inside considering its age I think.

Well see how it goes though but I'm hopeful.
 
You actually mow grass in AZ?

mac 'learned something new everyday' gyvr
 
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