®

NATIONAL 68 SR & DL TRIPLEX

TROUBLE-SHOOTING

DANGER

All adjusting must be made with the engine off.

Do not do any investigation of the working parts of the machine with the motor running. Always turn the engine off!

Tractor Unit

 

Situation

Things To Check

 

 

 

 

 

 

Engine will not start

Turn ignition switch to on

 

 

Ensure that there is sufficient gasoline (petrol) in the tank

 

 

Make sure safety switches are making contact and mowing clutch is in

 

 

neutral

 

 

Look for a loose wire on ignition or spark plug wire not connected

 

 

Interlock system inoperative—check wiring, see "Electrical Diagrams"

 

 

Operator must be positioned on seat to depress safety switches

 

 

(Model 68 DL only)

 

 

 

 

 

Mower will not move

Differential gear selector must be in one of the drive positions

 

 

Engine drive clutch must be engaged

 

 

Drive belts too loose (see "Drive Belt Tension" in Maintenance section)

 

 

Visually check to see that pulleys are not slipping on shafts

 

 

If everything above is OK, check for a damaged gear(s) in the differential

 

 

gear box

 

 

 

 

 

Mower will not stop

Ensure that the main clutch is disengaged (brake will not stop engine)

 

 

Brake adjustment or service may be needed.

 

 

 

 

Cutting Units

Situation

Things To Check

 

 

Cutting units will not turn.

Clutches may not be engaged

 

Look for anything that could be jammed between the reel and the bed knife

 

Drive belts or drive chain may need tightening

 

Visually check that both the drive pulleys and the shafts are rotating

 

 

Cutting units turn but

Reel bed knife position may be out of adjustment (see "Reel to Bed Knife

will not cut

Adjustment" in Maintenance section)

 

Drive belts or drive chain may need adjustment.

 

Visually check that both the drive pulleys and the shafts are rotating

 

 

Cutting units will not stop

Disengage all clutches

turning

 

 

 

Uneven cut

Set height of cut to the same height on each cutting unit (see "Cutting Height

 

Adjustment" in Operation section of this manual.)

 

Check to see if any part is bent

 

Something may be jammed in cutting unit pivots and/or lift pivots, preventing

 

the cutting units from floating

 

 

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National Mower 68 DL, 68 SR owner manual Trouble-Shooting, Situation Things To Check

68 SR, 68 DL specifications

The National Mower 68 DL and 68 SR are two outstanding models in the world of lawn care, engineered for efficiency and ease of use. Both mowers offer a range of features tailored to meet the needs of both residential and commercial users, making them popular choices among landscapers and homeowners alike.

The National Mower 68 DL is designed with durability and performance in mind. It features a robust steel deck that enhances longevity while providing a clean and even cut. Equipped with a powerful engine, the 68 DL delivers high torque and swift acceleration, enabling users to tackle even the toughest grass and rough terrain effortlessly. The mower's advanced cutting system ensures that grass is cut finely and evenly, reducing the need for additional clean-up.

On the other hand, the National Mower 68 SR offers a self-propelled option, allowing users to move with ease across various landscapes. This model incorporates hydrostatic transmission technology, which provides smooth, variable speed control. This feature is particularly beneficial for those who demand precision in their mowing tasks, as it allow for adjustments on the fly, catering to changing terrain conditions.

Both models come with adjustable cutting height options, offering users the flexibility to choose their desired grass length. The easy-to-use lever enables quick and simple adjustments without needing tools, making the mowing process more efficient. Additionally, both the 68 DL and 68 SR are designed with ergonomics in mind, featuring comfortable handles and intuitive controls that minimize operator fatigue.

Safety is another critical consideration in the design of the National Mower 68 series. Both models come equipped with protective shields and safety switches to prevent accidental starts, ensuring that users can operate the machines with confidence.

For convenience, the mowers also feature large, easy-roll wheels that enhance maneuverability. The inclusion of a bagging system offers an option for collection of grass clippings, contributing to a cleaner lawn appearance post-mowing.

In summary, the National Mower 68 DL and 68 SR combine advanced engineering with user-friendly features that prioritize performance and safety. They are exceptional choices for anyone looking to maintain a pristine lawn with minimal effort, making yard work a more enjoyable task. Whether for home use or professional landscaping, these mowers stand out in their class, delivering reliable performance time after time.