Obviously, you are looking for more reach. The 025 / MS-250 isn't on my list of best saws, but while there are many detractors on this site, there are also many people that seem satisfied with those saws. Certainly, they are not pro saws. They are rated as class C, homeowner engines, and I have had more than a few of these saws on my work bench. I will park my negative bias right here. With an 18" bar, you can still pull a .325 pitch chain, but it is best served with 16" bar and chain, as others have long stated. If you must experiment, might I suggest visiting Bailey's Outdoor Power Equipment on line, and purchase an 18" WoodlandPro bar and chain combo, with the .050 gauge NK configuration. I have done this myself, and have had gratifying results. This will not cost you an arm and a leg, so if you are dissatisfied, you won't curse me too loudly. The chain quality is excellent for the money. There is usually a $10 off first time buyer offer.