10+ year old 21hp briggs and stratton in the craftsman finally took a dump last weekend. Just ordered a 19hp B&S motor, do I need to break this motor in first and do I need any special oil? B&S website says run 30 weight, take it easy for 5 hrs, then change oil with more 30 weight and run it normally. Any input?

Yeah just put it to work like normal on a mower and change it after the first couple hours of use to get the break in oil and sediment out. Just use the 30 wt as it says nothing special.

Does it have a bagger or blower vac on it? If so i wouldn't use them for the initial break in period.

10% less HP is going to be noticeable on the small rig.

Edited October 10, 20177 yr by Wild and Free

Yes, a bagger. Running the blades and bagger puts more load on it for sure. When the original motor was on its way out, driving was fine, but engaging the blades was pushing oil out the drain tube.

I replaced the head gasket, but it was still pressurizing the crankcase, rings must be shot, I could still see the cross hatching in the bore.

 

So, should I just drive it at first, or actually mow, just not at full speed? 

 

 

I would just mow like normal without the blower vac for a couple hours change oil then let her buck.

I've changed the oil and filter in this thing twice since new last fall, and now it is leaking oil from everywhere possible. Everywhere there is a gasket, fill tube and dipstick area, all leaking oil.....not major, but enough. Can I assume the crankcase is pressurized? and can I add a breather like our trucks or do I have to spend money and replace the pcv valve? From reading online it looks like the fuel pump requires vacuum from the engine to suck fuel, but I don't know diddly about little engines.