I am not mecahanicaly inclined and I checked my oil today in my xr650L and it is a little low. The manual for the XR650L recomends 10w30 oil but all stores are closed today. I have some (sae 20W-40/API SJ non-friction modified four stroke oil I use for my yamaha's (dirt and street). Can I add this to what I have in it or is that a bad idea? Im in Mississippi and it very humid and hot here during the summer.