OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers B&S oil amount for 2.5hp

My "new" S-B45 has an old B&S 2.5hp 'Easy Spin' motor. The filler cap is just that, viz. no dipstick. Do I fill it to just near the top or ? It has square headed sump plugs front & rear, both seem equally worn/used - so to drain I take out both?

And probably obvious to those in the know but . . . is there a "follow this post" button that flicks you an email when there's a reply? tia

Hello PhilCal,

You really don't need to undo those other two originally square headed plugs as that just makes a mess on the machine.

Just open the filler and place with your other hand an empty Ice Cream container directly under the filler neck while tilting the machine backwards. You can lay it all the way back and thus all the oil will come out.

When refilling it just fill it with new oil up to the bottom of the visible casting of the filler neck.

That's it !

Cheers,
BB

You're a champ Bonnar Bloke, thank you.

As B_B has said, it's easier to tip the mower back, and get the old oil out that way. If you really want to pull a drain plug, the rear one won't make quite as much mess.

Stated oil capacity for these engines is 600mL, but don't be surprised if you can't get quite that much in.

Correct fill level is to the lower edge of the filler opening; i.e. just to the point of overflow, with the mower parked on a level surface.

We recommend the use of a straight SAE30 oil, not a multigrade, in side valve Briggs engines. They always seem to burn a fair bit more oil, with multigrade.

ta Gadge