Arrowmax Clutch Spring Tool
Arrowmax release a clutch spring tool CNC-machined from lightweight aluminium and designed for 1/8 and 1/10 on-road nitro engines. Compatible with most current centrifugal axial clutches, the tool allows to easily mount/dismount the clutch spring preload collar and make fine preload adjustments. For mounting simply insert the preload adjusting collar into the tool, press it onto the spring, and then start threading it onto the clutch nut. Dismounting is done in the reverse order. For preload adjustment the tool is placed over the collar and tighten or loosen the collar.
Source: Free Max [freemaxmp.com]