I had two flat tires on my foreman and I aired them up with an electric pump and air was leaking around the rim. So wat I done is I went to a tire place close to my house and bought some grasshoper sealent and it sealed up my valve before I even got air in the tire. Then I had to go get another valve put back in the tire. So now I use simple Fix a flat from wal-mart..haha. Now my tires never leak! I would say fix a flat is your best bet.