5

Maintenance

WARNING

Before inspecting, cleaning or servicing the machine, shut off engine, wait for all moving parts to come to a complete stop, disconnect spark plug wire and move wire away from spark plug. Failure to follow these instructions can result in serious personal injury or property damage.

Loading and unloading the tiller into a vehicle is potentially hazard- ous and we don’t recommend doing so unless absolutely nec- essary, as this could result in personal injury or property damage. However, if you must load or unload the tiller, follow the guidelines given next.

 

 

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3. Have an assistant pull the Reverse Clutch Control

 

 

 

 

 

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knob all the way out and hold it in that position.

 

 

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Measure the length of the cable wire between the end

 

 

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of the threaded cable adjuster (A, Figure 5-5) and

 

 

the end of the Z-fitting (B) to which the cable wire is

 

 

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attached.

 

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4. The belt tension is ideal if the cable wire length

 

 

 

 

 

 

measures between 1/8” to 1/4”. If it is less than 1/8”

 

 

 

(and if there is no reverse action when the tiller is

 

 

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running), then make the following adjustments

 

 

 

 

 

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NOTE: If the length is more than 1/4”, no adjustment is

 

 

 

needed—as long as the reverse action functions properly.

Figure 5-4:To check forward belt tension, take two measure- ments of the overall length of the boils in the spirng — first with the clutch bail open, then with the clutch bail closed against the handlebar.

e. Repeat Steps 2 and 3 to re-measure the length

 

 

 

 

of the spring. When the second measurement

 

 

 

 

is between 1/16” -to- 3/16” longer than the first

 

 

 

 

measurement, retighten the hex nut (C) against the

 

 

 

 

top of the adjuster (B).

 

 

 

 

Replacement Belt Information

 

 

 

 

If the drive belt needs to be replaced, see your local

 

 

 

 

authorized dealer or refer to the Parts List for ordering

 

 

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information. Use only a factory-authorized belt as an

 

 

“over- the-counter” belt may not perform satisfactorily.

 

 

 

 

The procedure requires average mechanical ability and

 

 

 

 

commonly available tools.

Figure 5-5: Measure cable wire length to check for correct

FORWARD CLUTCH BAIL ADJUSTMENT

reverse belt tension..

 

 

5. Release the Reverse Clutch Control knob.and then

If the Forward Clutch Bail does not function properly, first

unthread the inner jam nut (C, Figure 5-6) one to

check that the forward drive belt is adjusted properly (see

two turns. Pull the threaded cable adjuster (A, Figure

Checking and Adjusting Forward Drive Belt Tension). If

5-6) to the left until the inner jam nut (C) touches the

this fails to correct the problem, contact your authorized

bracket.

 

 

 

dealer for service advice.

6. Prevent the inner jam nut (C) from turning and

 

CHECKING AND ADJUSTING REVERSE

tighten the outer jam nut (D) against the bracket.

DRIVE BELT TENSION (Models 643B & 645A

Prevent the outer jam nut (D) from turning and

only)

tighten the inner jam nut (C) against the bracket.

7. Measure the gap by repeating Step 3. Readjust as

It is important to maintain correct tension on the reverse

needed by repeating Steps 5 and 6.

drive belt. A loose belt will cause the tines and wheels to

8. Reinstall the belt cover.

 

slow down – or stop completely – even though the engine

 

 

 

 

 

is running at full speed.

 

 

 

 

When checking belt tension, also check the belt for

 

 

 

 

cracks, cuts or frayed edges and replace it as soon as

 

 

 

 

possible.

 

 

 

 

• Check belt tension after the first two hours of break-in

 

 

 

 

operation and after every 10 operating hours.

 

 

 

 

To Check Reverse Belt Tension:

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1. Stop engine, wait for all parts to stop moving and

 

 

 

 

 

disconnect spark plug wire.

 

 

 

 

2. Remove screw in plastic belt cover and slide belt

 

 

 

 

cover (which is attached to forward clutch cable) out

 

 

 

 

of the way.

 

 

 

 

 

Figure 5-6: Move threaded adjuster (A) to left to increase

 

belt tension..

 

 

 

20

Page 19 Page 21
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Image 20
Bolens 643C Only, Replacement Belt Information, Drive Belt Tension Models 643B & 645A, To Check Reverse Belt Tension
Page 19 Page 21

643B, 643C, 645A specifications

The Bolens 645A, 643C, and 643B are celebrated models in the lineup of Bolens garden tractors, known for their durability and versatility. These machines, produced during the 1970s and 1980s, are vintage favorites for homeowners and garden enthusiasts seeking rugged equipment for their gardening needs.

The Bolens 645A is especially noted for its robust build and powerful performance. Equipped with a 7-horsepower engine, the 645A can tackle a variety of tasks, from mowing to snow removal, making it a multipurpose tool in any garden or landscape. One of the main features of the 645A is its hydrostatic transmission, which allows for seamless speed adjustments, providing exceptional maneuverability in tight spaces and varied terrain.

Similarly, the Bolens 643C and 643B models boast impressive features and capabilities. The 643C is renowned for its compact yet powerful 6-horsepower engine. It includes a gear-driven transmission, which offers reliable power transfer and increased efficiency while operating under demanding conditions. The steady performance of the 643C makes it ideal for smaller properties, where precision and control are paramount.

The 643B, while slightly less powerful than its sibling, still holds its own with a solid 5-horsepower engine. It is particularly favored for its ease of use and relatively low maintenance requirements, making it a perfect choice for casual gardeners or those new to the world of garden tractors. Its straightforward controls and simple mechanisms ensure that users can quickly learn to operate it proficiently.

All three models are engineered with a focus on user comfort. The seating is designed ergonomically, allowing users to operate for extended periods without discomfort. Additionally, the accessibility for maintenance tasks is a notable characteristic, ensuring that both professional and amateur gardeners can perform regular upkeep with ease.

In terms of technology, these models utilize straightforward mechanical designs with minimal electronic components, which reduces the likelihood of breakdowns and simplifies repairs. The rugged construction of the chassis and attachments demonstrates Bolens' commitment to longevity and resilience, making these tractors a solid investment for any gardening enthusiast.

In summary, the Bolens 645A, 643C, and 643B models stand out in the garden tractor market due to their powerful engines, user-friendly designs, and robust construction. They represent a blend of efficiency and reliability, catering to a wide range of gardening tasks and maintaining a loyal following among vintage equipment enthusiasts.
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