What weight for a generator engine, B&S twin

[Nitrox]

Bought a used Porter Cable generator early this year, 8000 watts, 11000 surge. It has a twin cylinder B&S air cooled engine. I have a few 5 quart containers of Mobil 1 10w30 on hand and was considering using it in the generator engine. Would this be heavy enough oil for my air cooled generator?

 

[Ugly3]

Briggs is recommending full synthetic 5w30 for all their air cooled engines. Briggs Oil Recommendation

 

[brian fix]

Schaeffers 5w-40 would excell in this app,,,,,,,,,,,,,,BL,check site sponsor

 

[philipsearcy]

I have the same generator as you. Have been running Mobil 1 5W-40 since new. Philip.

 

[416Rigby]

5w-40 and 15w-40 oils are good for air-cooled engines. Mobil TSUV and Redline 15w-40 work great.

 

[MN Driver]

I have used 10w-30 in my B&S 7HP engine. It's not a twin but I've used it through a gallon of gas without shutting it off and when I drained it out immediately after shutting it down, the oil wasn't hot enough to prevent me from putting my hand in it to grab the drain plug that fell in the pan. There isn't a recommendation for a 40 weight so I stuck with the 10w-30 because it just didn't seem to get hot enough for it. I like the Briggs recommendation of synthetic, yet mine consumes oil (possibly because of such low hours) so I won't be using synthetic.

Just curious, how hot does the oil drain out of your B&S twin engines on your generators?

 

[JAYCEE]

I have a B&S twin from 1987 on a lawn tractor. I use ST 5w-30 full synth in it all year long. No problems.

 

[wileyE]

It's a briggs. Use up all the partial qt's on the shelf.