Briggs and Stratton desludging

[Oldtom]

Bought a 22 inch MTD mower off Craigslist for dirt cheap. Engine is 3.75 HP Briggs. Foam air filter element was missing and the oil looked like black sludge. Installed a new air filter, new plug, and filled with some 5w 30 PYB I had lying around. The mower runs very well but is probably sludged inside. I want to do two more oil changes at 4 hours each to desludge the engine and remove any dirt from the missing air filter. Which is the better cleaning oil, Supertech 30 WT HD, Supertech 10w30, or Supertech 15w 40?

Thank you in advance for any advice.

 

[mx5miata]

I'd go with 30w HD

 

[Trav]

I would drain the oil and fill it with Kerosene, let it sit for a couple of days then drain and refill with HDEO 5w40.

 

[Donald]

Originally Posted By: Trav
I would drain the oil and fill it with Kerosene, let it sit for a couple of days then drain and refill with HDEO 5w40.


I would pull the plug and give the starter a few pulls every time you walk by. Maybe squirt some kerosene down the spark plug hole each evening.

Mix it up.

You have no idea if it is sluged or not. Dirt/dust into the engine will blacken the oil and cause wear but may not cause sludge. Sludge is mainly due to ignoring oil changes.

 

[Trav]

Its a lawnmower, fill with Kerosene and tip the engine to fill the cylinder from behind with the plug in, it will fill it and loosen all sorts of garbage. Just pull the plug, clean/replace it and thoroughly drain the crank case after it sat a while.

 

[Lawn_Care]

SuperTech 15w40 is perfect for a small air cooled engine like that, and a few short OCI's (3-4 hours each) should have it cleaned out in no time. Not trying to start a war, but a couple oz. of MMO or Seafoam will help speed the process.

 

[bubbatime]

I've seen some bad oil but I have never seen sludge oil in a mower, unless perhaps it sat outside and water got in it.

Just change the oil with SAE30. Then do another change in about 10 hours, then once a year after that.

But really, my best advice is to keep monitoring Craigslist and get a better mower. No way I could mow with one of those old Briggs 3HP flat heads. They are dogs.

Sell your current mower for more than you paid and upgrade to a better mower, for likely the same amount of money. You can especially find a good deal if it has a bad carb on it. Slap a new $13 carb on it, and good to go. I have literally bought $650 Toro Super Recycler, two years old, with a gummed up carb for $5. person bought a new mower, and just wanted it gone.

 

[Lubener]

A couple 5 hour oil changes(30HD), no kerosene and once a year thereafter.. It's just a lawn mower and it will be fine. I have seen those B&S engines which never had an oil change kept on performing.

 

[92saturnsl2]

15w-40 would be my choice. Or just change oil and use it-- those engines don't really care what's in them or how sludged up they are; they typically last longer than what they're bolted to, especially an MTD.

 

[CT8]

i would just cut the lawn and do a few changes to see how much crud comes out.

 

[wag123]

Originally Posted By: Lubener
A couple 5 hour oil changes(30HD), no kerosene and once a year thereafter.. It's just a lawn mower and it will be fine. I have seen those B&S engines which never had an oil change kept on performing.

+1