MTD 675 thru 689 - Manual (Page 8)

1 1
Gear Box (Self-Propelled Models Only) —The gear
box is lubricated with 3 ounces of High Tenp. (450°
F.) grease. Order part number 737-0223. Pf riodically
check lubricant level by removing the two se f-tapping
screws on the gear box cover and lifting off t ie cover.
Do not change grease; simply add if necessary.
ENGINE
Refer to the separate engine manual fo' engine
maintenance instructions.
Maintain engine oil as instructed in the ¡separate
engine manual packed with your unit. Read and follow
instructions carefully.
Service air cleaner every 25 hours under noi mal con­
ditions. Clean every few hours under extremely dusty
conditions. Poor engine performance and flooding
usually indicates that the air cleaner should be ser­
viced. To service the air cleaner, refer to the separate
engine manual packed with your unit.
The spark plug should be cleaned and the gap reset
once a season. Spark plug replacement i;; recom­
mended at the start of each season; chec< engine
manual for correct plug type and gap specific itions.
Clean the engine regularly with a cloth or brush. Keep
the cooling system (blower housing area) clean to
permit proper air circulation which is essential to
engine performance and life. Be certain to re ¡move all
dirt and combustible debris from muffler area
BELT REPLACEMENT (Self-Propelled Models Only)
1. Remove the nozzle or impeller guard from front of
blower housing.
2. Remove hex bolt and lock washer from center of
impeller. See figure 18. A 9/16" socket wrench
with extension is needed.
3.
4.
Remove hand knob and cupped washer from top
of housing.
Remove two self-tapping screws which hold the
belt guard. See figure 19. A 3/8” wench is
required. Lift off belt guard.
FIGURE 19.
5. Slide belt off the impeller pulley. Slide housing
and impeller off engine crankshaft. Be careful to
not lose square key. See figure 20.
Engine
Crankshaft
P.T.O.
Pulley Square
Key
FIGURE 20.
6. Slide impeller and blower housing assemblies off
crankshaft.
7. Remove belt from P.T.O. pulley and install new
belt. See figure 20.
NOTE: When reassembling the new belt, the aid of
another person will be helpful.
8. Turn the crankshaft until the keyway on shaft is
directly on top. While holding housing assembly
and impeller assembly, line up the keyway on the
pulley with the key on the crankshaft, and slide
housing and impeller assemblies onto crankshaft.
9. Secure impeller to crankshaft with hex bolt and
lock washer, removed in step 2. Tighten securely.
10. Slip belt over impeller pulley. Reassemble the
belt guard.
11. Secure blower housing with hand knob and wash­
er.
12. Reassembie the nozzle or impeller guard.