sawmikaze, you’re right. The Semi‑Pro Series kits — including the new “Mini” — were designed from a clean sheet for users who prefer the stock look of the 500i or 661. We could have simply squeezed a filter under the OEM cover, but that’s never been our approach. It took a lot of development work to balance CFM, foam density, oil‑holding capability, cleaning intervals, and overall function while still fitting under the stock cover. The MaxFlow Mini meets all of those goals.
The Pro‑Series kits for the 500i and 661 are aimed at a different type of user. They use a larger MAX cage and a much bigger filter element with significantly more surface area, higher airflow, more oil retention, and the longest cleaning interval available. To support that performance, we supply a form‑fitted cover designed specifically for the system.
The 500i MAX can be installed without trimming the shroud when running a short bar. However, the Stihl anti‑vibe mounts are very soft, and longer bars can flex enough to let the cover make slight contact with the engine shroud. To avoid that, we recommend trimming the baffle (which keeps the stock shroud untouched) or trimming the shroud itself, which is the preferred option for Pro users.
The 500i and 661 have been the go‑to saws for professional users for nearly a decade, and most have no trouble with the small trim adjustment.
For users who want a completely no‑mod installation, the Mini provides excellent performance — just not quite at the level of the Pro‑Series MAX.
