McCulloch PRO MAC 610 - Sawdust Guard and Cooling Fins; DSP Valve (PM 650)

9. Pull the starter rope gently until the starter ratchet en-
gages the pawls on the flywheel, and the starter housing
settles against the saw. Install the starter housing screws
and tighten securely.
10. Re-install the bar and chain and the CHAIN BRAKE, fol-
lowed by installing the spark plug and spark plug wire.
SAWDUST GUARD AND COOLING FINS
The air inlet openings of the sawdust guard and the cylinder
cooling fins must be kept clean or the engine will become
overheated during cutting operations. Cooling fins are easily
cleaned after removing the CHAIN BRAKE.
1. Remove the starter cover and clean out the openings in the
sawdust guard. Use a small wooden scraper to remove dirt
and sawdust packed into the openings. Use a soft bristle
brush to finish cleaning the guard. Make sure the starter
shaft turns freely and easily.
2. Clean the vanes on the flywheel and the other parts of the
engine that became visible when the starter cover was
removed.
3. When re-installing the starter cover, pull the starter rope
slowly so the starter can engage the flywheel properly, and
be certain the guide post is positioned in the locating hole
in the fan housing. ®
4. Remove the CHAIN BRAKE. Remove all dirt, grass, wood
chips, etc. from the cooling fins on the cylinder head. Use
a thin scraper or a stiff brush.®
DSP VALVE (PM 650)
If the valve does not close during acceleration to wide open
throttle, the DSP valve should be removed and inspected.
After removing the CHAIN BRAKE, remove the DSP valve
using a 7/16 inch deep socket wrench.®
The valve seat area should be free of carbon. The valve
assembly can be washed in a clean solvent to remove carbon
accumulation at the valve seating area.
CAUTION: Do not submerge the plastic knob as some sol-
vents wiil dissolve plastic.