Just did my 50 hr. engine oil and filter change, the manual says it will take 3.7 qts. of oil with a filter change, thats what I put in the engine, but on the oil dipstick it shows that its low, its just a bit past the half-way mark, so I could maybe add about 4 to 8 ounces to put at the top mark, I ran the tractor for a few minutes and let it cool down, still shows as I described above, dipstick is fully seated when I remove it and check it, anybody ever encounter this??