Bolens 450 Series Service Manual

This Operators Manual covers a range of product 
specifications for various models. Characteristics and fea-
tures discussed and/or illustrated in this manual may not 
be applicable to all models. MTD LLC reserves the right 
to change product specifications, designs and equipment 
without notice and without incurring obligation.

IMPORTANT: Because this manual covers several 
different model units, different starting instructions may 
apply to your particular engine. Some engines may have 
a fuel petcock, some may not. Some engines may have 
On/Off switches, other may not. Some units will utilize a 
choke system, while others will require priming.  These 
factors depend on what make and model engine comes 
with your particular unit. For these reasons, please refer 
to the engine operator’s manual for the correct starting 
procedure.
1.  Attach spark plug wire to spark plug. Make certain 

the metal cap on the end of the spark plug is fastened 
securely over the metal tip on the spark plug.

2. 

  Move choke lever on engine to CHOKE position. (A 

warm engine may not require choking).

  Engines with primer:
  Prime engine as instructed in separate engine manual.
3.  The throttle control lever is located on the engine. 

Move engine throttle control lever to FAST or START 
position. See Figure 4-2.

4.  Grasp starter handle and pull rope out slowly until 

engine reaches start of compression cycle (rope will 
pull slightly harder at this point).

NOTE: A noise will be heard when finding the start of 
the compression cycle. This noise is caused by the flails 
and fingers, which are part of the shredding mechanism, 
and it should be expected until the impeller reaches full 
speed.

5.  Pull rope with a rapid, continuous, full arm stroke. 

Keep a firm grip on starter handle. Let rope rewind 
slowly.

6.  Repeat the previous steps until engine fires. When 

engine starts, move choke control (if equipped) 
gradually to RUN position. 

1.  Move throttle control lever to STOP or OFF position.
2.  Disconnect spark plug wire from spark plug and 

ground against the engine.

NOTE: See your engine manual packed with your unit 
for more detailed instructions.

Yard waste such as leaves and pine needles can be 
raked up through the hopper assembly for shredding. 
After material has been shredded by the flail blades 
on the impeller assembly, it will be discharged out of 
opening or into catcher bag. Do not attempt to shred 
or chip any material other than vegetation found in a 
normal yard (i.e. branches, leaves, twigs, etc.) Avoid 
fibrous plants such as tomato vines until they are 
thoroughly dried out. Twigs and small branches up to 3” 
(2” for Model Series 450) in diameter  can be fed into 
the chipper chute.

1.  With one hand grasp the handle at the top of the 

hopper assembly and lift slightly.

2.  With the other hand pull out on the release rod 

and lower the hopper assembly to the ground. See 
Figure 4-1.

1.  Un-clip drawstring and loosen bag from chute 

deflector opening.

2.  Empty bag and reattach to the discharge chute 

opening. Pull on the drawstring until the bag is tight 
around the chute opening and clip the drawstring 
tight against the chute deflector.

IMPORTANT: The flail screen is located inside the 
housing in the discharge area. If the flail screen 
becomes clogged, remove and clean as instructed in 
SECTION 5: MAINTAINING YOUR CHIPPER SHRED-
DER. For best performance, it is also important to keep 
the chipper blade sharp.

NOTE: 

A noise will be 

heard when finding the start 
of the compression cycle. 
This noise is caused by 
the flails and fingers, which 
are part of the shredding 
mechanism, and it should 
be expected until the impel-
ler reaches full speed.

STOP